DDR4 specs and version number ID - Insight to what DDR4 ram you have Part 1 of 2


Jul 13, 2015
DDR4 Overclocking
SPD Data

Platform-specific tips
LGA2011-3 (X99)
4Gbit Hynix MFR Guide
1151 processors have two relevant voltages on the processor - VCCIO and VCCSA. Similar to Haswell, higher performance settings - including tight timings at relatively low speeds - need higher VCCSA. Higher speed settings in terms of pure MHz need higher VCCIO. Note that significantly overshooting VCCIO may reduce stability.
AM4 (X370/B350)/TR4 14nm(B450/X470/X550/X570 Revision Req)
For high performance settings, increased SoC voltage is needed. 1.05V is a good starting point, absolute maximum is 1.2V.
Ryzen 1000 initially hated dual rank memory and would limit your speed to around DDR4-2666 to DDR4-2933. Newer BIOS revisions improve this (dual rank DDR4-3200 seen working on first gen with Pinnacle Ridge AGESA) but single rank is still better.
Hynix was a total pain on Ryzen when the platform first launched, although things are much better on newer BIOS revisions. If you bought a cheap 3000C15 or 3200C16 kit and are now struggling, there's more in-depth discussion here.
Micron and Samsung usually work fine with XMP. Some bad boards have issues with 4Gbit Samsung.
8Gbit ????
Found on some "Gloway" sticks binned at 3000 16-18-18-38 1.35V, as well as some Kingbank, Teclast and Tigo modules sold in China. Started to leak into value series modules from more "contemporary" companies like Silicon Power and Patriot, partially marked (eTT?). Multiple reports originating from China draw a similarity in OCing characteristics between these and Hynix CJR but more data would never hurt. Listed as A-die by Thaiphoon Burner.
4Gbit MFR
Characteristics: Typically DDR4-3000 or so, DDR4-3333 at best with optimal voltage, CL12 and tRCDtRP 15-16. Very very picky about voltage, rolling over at 1.5-1.7V depending on stick and cooling. Asus POST codes are supposedly 55 for not enough voltage and 41 for too much.
Found on: Corsair ver5.29.
Platform preferences: Not sure, probably hates Ryzen.
Recommended for: X99 daily, disposal in fire.

4Gbit AFR
Characteristics: Very good voltage tolerance for benching, doesn't roll over with high voltage. DDR4-3600 12-17-17 at 1.65V, potentially DDR4-4000 CL13 with a 1DPC board and more voltage. Comes pretty close to E-die but is more picky about board quality. Found on: Corsair ver5.20, 4Gbit HyperX with Hynix marking rated for DDR4-3333 and higher.
Platform preferences: Not sure, probably hates Ryzen.
Recommended for: Budget Intel benching if you can't get 4Gbit E-die.

4Gbit BJR
Found on: some 4GB Kingston HyperX Modules
All that's known is this is listed on the Hynix website with jedec bins up to 2666C19 (the same as other Hynix ICs, except 8Gbit CJR which has JEDEC bins to 3200). A user was able to POST 3066 16-15-15-34 on Zen+.
Another user notes on Zen2: Scales rather linear with voltage up to 1.5V, boots 16-18-18-18-38 up to 3466MHz and 18-19-19-19-40 at 3600MHz. Hard wall at 4266MHz CL22-24-24-24-46 1.55V (single stick, single channel).

8Gbit MFR
Found on: Presumably Corsair ver5.39. Some Kingston HyperX modules from 2016-2017. Still obtainable in G.skill products as recent as 2020 Oct (e.g. a 2x8GB 3000 15-15-15 Rip jaws V kit with a 042...8821M code).
Platform preferences: Gets on with Intel stuff a lot better - supposedly this is something to do with needing 2T command rate. Not a big deal with more recent AMD BIOSes.
Recommended for: Running a 3200C16 kit at XMP.

8Gbit AFR
Found on: Presumably Corsair ver5.30.
Platform preferences: Gets on with Intel stuff a lot better - supposedly this is something to do with needing 2T command rate. Not a big deal with more recent AMD BIOSes.
Recommended for: Running a 3200C16 kit at XMP.

8Gbit BFR
Characteristics: Voltages and scaling currently unknown.
Found on: Presumably Corsair ver5.31. Seen in the wild on a 2666 16-18-18 1.2V rated Corsair Vengeance LED kit. However, does not appear on Hynix website as of the end of 2018 despite AFR still being in production.
Platform preferences: ?????
Recommended for: ?????

8Gbit CJR
Characteristics: Seen in the wild doing 4000 18-22-22 stable. Scaling varies, voltages higher than 1.45V seem to cause accelerated degradation.
A unit with a down binned (4Gbit) version hit 3466 16-18-19 1.35V with an Asrock B350 board and first gen Ryzen. Another was reported doing 3600 16-19-20 on Zen2 and an Asus B350.
Found on: Corsair ver5.32. Seen in the wild on G.Skill Sniper series 3600 19-19-19, some 3600C18 kit, Patriot 3733 17-21-21, and a late 2018 3000C15 Corsair Vengeance LPX stick. Almost guaranteed in the 3600 16-19-19 G.Skill bin. Some Team, Thermaltake Tough RAM, Gigabyte Aorus and similar modules.
A cut down (4Gbit density) version of these goes under the "1JR" moniker and can be found in Essencore/Goodram 4GB sticks from 2019 and G.Skill 4GB and dualrank 8GB sticks from 2019 onwards with 04240H48211 label code. 16Gbit AJR has seen similar treatment (down binning to "8Gbit 1JR").
Platform preferences: Seems to be fine on both Intel *lake and AMD Ryzen. Issues reported on X99.
Recommended for: Higher-end daily without the B-die tax.

Characteristics: Suspiciously similar to CJR. Tested DDR4-2666 OEM stick did 3600 18-19-19-40 1.2V on Ryzen (cheap 1DPC board), and booted 3733 unstable. No noticeable voltage scaling going to 1.45V. Seems to have its tRCD tRP behaviour flipped compared to such of CJR (instead of tRP, tRCD is an outlier).
Found on: Some Dell Alienware OEM systems use Hynix OEM sticks carrying this IC. Corsair ver5.38 (units have been seen in the wild). Occasional guest in G.skills (042...882xJ). Not documented on the Hynix website.
Platform preferences: Certainly gets on fine with Ryzen, be surprising if it doesn't like Intel *lake. Presumably has issues on X99.
Recommended for: Might be a good value daily option if you find a cheap used set.

16Gbit MJR/MFR
Characteristics: Tested DDR4-2666 OEM SODIMMs did 3600 18-20-20-32 1.25V on X299 in dual channel. Only able to run 3466 18-20-20-32 1.25V on X299 in quad channel. Doesn't seem to like low tRCD or tRP, and negative scaling appears to be present past 1.25V however, 2020 has seen this IC being used in sticks rated for 1.35V. Doesn't appear to like tRCD/tRP being decoupled. Seems to have a bit of potential. SPD on the OEM SODIMMs claims they're MFR, could be Thaiphoon Burner not being aware of their existence at the time.
At the same time, G.Skill bins these all the way to 4000 18-22-22 at 1.4V, and to 3200 14-18-18 or 3600 16-22-22 at 1.45 so mayhap the scaling situation isn't that straightforward ¯\_(ツ)_/¯
Found on: Apple 32GB OEM SODIMMs or pulls from laptops. Not documented on the Hynix website but available in OEM Hynix sticks (incl. UDIMMs). One 2x32GB 3600C18 Patriot Viper Blackout kit (with a DTBP partial on the ICs). Common in 32GB G.Skill sticks (not the double-height DC series), with the 042 code ending in S820M.
Platform preferences: Requires a BIOS update for X299, but runs fine otherwise. Should run fine on Ryzen as well as *lake.
Recommended for: Reasonably fast high density SODIMMs on X299.

16Gbit AJR
Found on: OEM Hynix sticks and a bunch of Thermaltake Tough RAM RGB, Patriot (one 2x16GB 3200C16 Patriot Viper Steel kit was seen with a 0BAJ code which suggests 16Gbit AJR) and G.skill products: from Rip jaws SODIMMs and Aegis (cut down versions with DTBU partials on the ICs, code 042...88211) to higher tier SKUs like a yyww 2102 2x32GB G.Skill TridentZ RGB 3200 16-18-18 kit, with the 042 code on the stickers ending in S820A.
No overclocking reports at this time but its presence in more potent G.Skill Rip jaws and TridentZ bins like 3600 18-22-22 and 3600 19-20-20 (codes S820A, S821A) seems quite telling.

16Gbit CJR
Recently seen on Corsair 3600MHz kits with 32GB DIMMs. No overclocking results at this time.
Otherwise found on stock photos from Hynix advertising the release of 1z nm DDR4 SDRAM. Actual units (8GB and 16GB size) have started leaking into retail, too, and seem to be common in prebuilds. The datasheet is public; stock bins up to 3200.

4Gbit ????
New IC originating from China, seen in Geil sticks and G.Skill Values sold in the country, with the 042 ending in 97A. A single available report had them max out at 3066 16-18-18 1.35V on a Ryzen 4750G. Thaiphoon Burner reports them as A-die.

NB: Micron also sell ICs branded as Spectek. They have the same Micron part numbers and the same characteristics, although it's possible they're lower binned.

4Gbit Rev.A (D9RB* and D9RG*)
Thaiphoon Burner seems to have issues reporting the revision on these, however they are identified by the first part of the part number coming out as "MT40A512M8??"
: Pretty bad. Best case you might get 3000 14-16-15-28 with tRCDWR 8 - worst case you may be stuck at 2666. D9RG has part numbers ending in E which seems to indicate a slightly better JEDEC bin - D9RB may be a bit worse.
Apparently rolls over with voltage immediately at lower speeds - on one tested kit JEDEC was unstable at 1.35V! - but can scale at higher speeds, 3000 working alright at 1.5V.
Found on: Older Micron OEM and low-end Crucial 4GB single ranked (1Rx8) and 8GB dual ranked (2Rx8) sticks (check IC code). Corsair ver3.20. Presumably early Kingston 4GB sticks with M08 marking and 8GB with M16 marking. Most early, slow stuff has at least a chance of getting these.
Platform preferences: Doesn't seem to be fussy, but the limited MHz means it's only useful on X99.
Recommended for: Allegedly good sticks are decent on X99. Mostly seems to need a lot of patience for worse results than more recent ICs.

4Gbit Rev.B (D9TG*, D9VCB, various others in non-desktop packages)
Characteristics: A test kit rated at 3000 15-17-17 1.35V struggled to do tighter or faster (even 3066). With looser timings may boot 3200-3466 - even on Ryzen 1000 with a bad board and early BIOS. Top sticks seen at 3466 16-19-19-24. Seems to need the tRCD pretty high.
Doesn't seem to like over around 1.4V(??), exact roll-over point will vary. D9VCB is the DDR4-3200 CL22 JEDEC bin.
Not to be confused with cut down 8Gbit Rev.B ICs. The difference lies in package size (4Gbit B is a "fatbody", at 9x10.5mm for 78-ball ICs, while cut down 8Gbit B with the same number of balls is narrower and sits at 8x12mm), which is also encoded in the part number.
Found on: Micron OEM and low-end Crucial 4GB single ranked (1Rx8) and 8GB dual ranked (2Rx8) sticks (check IC code). Corsair ver3.21. Presumably Kingston DDR4-2666+ 4GB sticks with M08 marking and 8GB with M16 marking.
Platform preferences: Not known for issues on any platform. Behaves very well on AM4, even in finicky/bad boards.
Recommended for: Great option for Ryzen or X99 daily - XMP profiles should work on basically any board (that supports memory tuning) and any bios. Bit low MHz for 1151 or X299.

4Gbit Rev.E (D9WQL)
Seen on Micron's site with part number MT40A512M8WE-075E:E - 075E indicates the DDR4-2666 CL18 JEDEC bin.

4Gbit Rev.F (D9WTD)
Characteristics: One user got 3733 12-(22/08)-15-24 1T with GDM on using Ryzen 1000 series with 1.7V memory voltage.
Found on: Corsair "ver3.22" 2400C16 JEDEC stick (relabeled; confirmed by package size). Some OEM Crucial sticks.
Recommended for: Seems to be a really great budget option for AMD, will suffer from the high tRCDRD on Intel. Much tighter tRFC than 8Gbit Rev.E.
Seen on Micron's site with part number MT40A512M8SA-075:F - 075 indicates the DDR4-2666 CL19 JEDEC bin.

4Gbit Rev.G (D9XJJ)
Seen on Micron's site with part number MT40A512M8SA-062E:G - 062E indicates the DDR4-3200 CL22 JEDEC bin. One of the options in OEM Crucial sticks (older FS, newer FRA series - the latter in dual rank form).

8Gbit Rev.A (D9SR*)
Characteristics: Dinosaur IC. Doesn't train normally in dual channel on any modern platform (1151, AM4), and requires you to train one stick before running dual channel. X99 seems fine with it. One sample dual rank kit doesn't overclock at all, another did 2733 16-(16/14)-14 1.2V and booted 2800, up from the stock 2400 flat 16.
Found on: older Micron OEM, Crucial and Crucial Ballistix Sport, and some older HyperX Fury sticks, stock speed 2666 and lower.
Platform preferences: X99, possibly Bristol Ridge.
Recommended for: Disposal in fire, running at stock.

8Gbit Rev.B (D9TBH, D9TNW, D9VG*, D9VF*, maybe others)
Characteristics: On Intel: pretty poor, needed extremely high tRCD (which means also high tRP on 1151), but can do tRAS exceptionally tight. Typical settings might be DDR4-3200 15-19-19-21 1.35V. On Ryzen: tRCDWR and tRAS both go as low as you can set them (still needs 19 tRCDRD), and tRP goes very tight as well, managing DDR4-3200 15-(19/08)-13-21 1T 1.35V.
Doesn't like voltage at all when running high MHz, appearing to have thermal issues.
Found on: Presumably Corsair ver3.31. Micron OEM sticks. Presumably midrange Crucial 8GB and 16GB sticks.
Platform preferences: Intel's combined tRCDtRP for 1151 is a big limitation on this ram, does great on Ryzen though.
Recommended for: Great option for Ryzen daily - XMP profiles should work on basically any board (that supports memory tuning) and any BIOS.

8Gbit Rev.D
Seen in a Corsair Vengeance RGB kit with DDR4-3000 15-17-17-35 1.35V XMP, also one of the ICs used by Kingston in their 2933 and 3200 JEDEC kits. Common in 2020 Ballistix 2666C16 8GB sticks and 2x8GB kits.

8Gbit Rev.E
Characteristics: 3466 14-17-17-36 and 3600 14-20-15-36 seen on Ryzen with GDM and 1.45V memory voltage, both fully stable. On Intel, seen at 3400 13-18-18-36 2T 1.5V stable. Techpowerup also got a 3200 16-18-18 dual rank stick to 3800 16-18-18, which seemed to be limited by failure to loosen tRCD.
Seems to scale pretty well with voltage for benching. Set a new memory frequency world record(!!!!) on 16th of May 2019 with an 8086K, memory and CPU both on LN2 cooling - DDR4-5726 24-31-31-63 at presumably very high voltage. Speed bins vary, from the baseline D9VPP and C9BHS seen in OEM sticks, to "hyper bins" like C9BJZ (which is seemingly being replaced by the similar C9BLD as of late 2020) in 3000C15 and 3200C16, and C9BKV in 3600+ kits.
Found on: Seen in 2019 Crucial Ballistix 8GB sticks with DDR4-3000 15-16-16 1.35V XMP. Presumably Corsair ver3.34 and Micron OEM sticks. Given the OC headroom, likely to be in higher rated Crucial kits as well - confirmed in DDR4-3600 Ballistix Elite and presumed in 2019 3200 and 3466 kits.
Platform preferences: Intel's combined tRCDtRP for 1151 is a limitation on this RAM, does great on Ryzen though with top tier daily settings.
Recommended for: Awesome option for cheap Ryzen daily, on Intel Hynix CJR is probably better as it does higher frequency and doesn't need tRCD as high, but this is still a very good option. Seems to be more consistent than Samsung B-die, so should outperform un-binned/OEM B-die on Ryzen. Turns out it's also good for smashing memory WRs - might be easier to run than B-die which probably contributes.

16Gbit Rev.B (D9XPF)
Found on: 32GB Corsair Vengeance LPX sticks, version 3.40. 32GB Ballistix sticks clocking at 3000C15 and higher. A cut down version is used in the 2x8GB Ballistix Max 5100 kit (albeit a pre-prod sample sported 8Gbit Rev.N judging by the full model number).
"Hyper bins" for these seem to be C9BLG (3000C15 to 3600C16) and C9BLH (4000C18 Ballistix MAX).

16Gbit Rev.E
New IC, not much is known.

Identification of Nanya ICs per revision is made harder by the fact that standard grade, fully marked chips do not feature the partial mark in the bottom right that partially marked, presumably eTT Nanya chips sport - and the latter are common all around (confirmed in Kingston, Patriot, Goodram and LC-Power sticks). This mark does not seem to indicate a particular revision.

4Gbit Rev.B (NT5AD512M8B1/2)
Rather old (2016-2017) IC which seems out of print, and not currently present on the Nanya website. Stock bins up to 2666.
Apparently, shares some DNA with Micron as its technical documentation features Z80B identifiers (link in Russian) which appear similar to Micron's Design IDs (and incidentally, such ID for Micron 4Gbit A is Z80A). It could be an outcome of this Micron-Nanya deal.
Never seen do anything above 3100.
Found on: various older Goodram sticks. Suspected in ver8.21 Corsairs.

4Gbit Rev.D (NT5AD512M8D3/4)
Listed on Nanya's website as of December 2019, stock bins up to 2933.
Found on: various 4GB Goodram IRDM sticks. Some 2x4GB Patriot Viper 3000C16/3200C16 kits (presumably with the 0EDC code) as suggested by the AMD Ryzen QVL (choose Nanya D-Die in the Memory IC dropdown menu). Suspected in ver8.23 Corsairs - this is stipulated by the fact that ver8.21 samples seen online are much older (year 2016 vs 2020). Also seen utilized as SSD cache.

8Gbit Rev.A (NT5AD1024M8A3/4)
Seen on Adata 3200 and 3600(!?!??) 16-18-18 2x8GB kits via QVLs, also in some Kingston kits and presumed in some RAM made by Powev (branded Gloway and Asgard). It's not unheard of for QVLs to have errors, the 3600C16 listing may have been one such error. Also suspected in ver8.30 Corsairs and highly presumed in G.skills with the 042/T42 code ending in 8850A (two samples have been seen: a Chinese Value series 8GB stick and a yyww 1805 4x16GB 2400c17 SniperX kit).
Reported by one user to hit 3200 16-18-18-40 at 1.35V.
Stock bins up to 3200.

8Gbit Rev.B (NT5AD1024M8B3/4)
On offer by one distributor, with a corresponding datasheet. Certainly exists in actual sticks, seen in the wild in 2019 Nanya UDIMMs (two different listings). Suspected (and, if Corsair IC labeling is to be trusted, confirmed) in ver8.31 Corsairs. Stock bins up to 2666.

8Gbit Rev.C (NT5AD1024M8C3/4)
Listed on Nanya's website as 'in development' as of December 2019, finalized and reached MP in 2020. Stock bins up to 3200.
Suspected in one 16GB Kingston Value RAM stick, as the SPD was seemingly programmed to Nanya, with the die stepping C. Same unit did 3200 16-17-18 in limited testing. Also seen utilized as SSD cache. Additionally, presumed in a recently found yyww 2105 2x8GB G.Skill Rip jaws V 3200 16-18-18 kit, with the 042 code ending in 8850C.

Powerchip (PSC)
4Gbit ??? (Rev.A, Rev.C)
Apparently, two revisions exist, both only in partially marked (eTT?) form. The former is presumed in bare 4GB G.Skill sticks with a 042...41A code while the latter is believed to appear in some Kingston Value Rams, judging from Kingston's IC part numbers and the SPD contents. The characteristic partial mark is XJ...-T at the bottom of each IC.
One report got the G.Skill variant to 3333 16-18-18 at 1.4V on a 9400F+Z390; however, AMD compatibility was shown to be atrocious, with a wall at tight 2400.
May have a connection with 4Gbit UniIC as the partials are the same format. Powerchip Semiconductor features a DRAM foundry service and span off companies like Zentel in the past, so contract production is quite possible. Found on: G.Skill Value series sticks with the 042 code ending in 41A. Some year 2018 Good rams and sticks made by Panram (branded Panram and Smartbuy). Some Kingston Value RAM sticks; a Kingston rebranded IC was also seen in use as DRAM cache in a Silicon Power SSD.

4Gbit Rev.D ("D-die")
Characteristics: Like E-die but worse, capable of DDR4-3733 CL15 to CL13. Similar to E-die in the CL scales with voltage well, tRCDtRP scales only a tiny bit with voltage.
Found on: Presumably Corsair ver4.23. Supposedly week 37 2012 and earlier G.Skill Rip jaws 3000+.
Platform preferences: Supposedly known for compatibility issues, but a tested kit even with oddball x16 ICs worked fine on Ryzen and Kaby.
Recommended for: X99 daily, solid budget option for low capacity mainstream daily.

4Gbit Rev.E ("E-die")
Characteristics: Does very high frequency (DDR4-4000+) on Intel *lake. CL scales very well with voltage and can run almost as low as B-die, RCD and RP scale a little bit with voltage but generally have to be raised in line with frequency increases.
Found on: Nearly all 4GB DDR4-3600 and faster sticks (slim chance of high bin AFR). Crucial Ballistix 4GB DDR4-3200. Corsair ver4.24.
Platform preferences: Recommended for: Intel daily, budget Intel *lake benching. Can get impressive frequency validations, but not competitive with B-die.

4Gbit Rev.T ("T-die")
Not listed by Samsung, but seen in the wild on an OEM DDR4-2666 dual rank stick from week 42 2018. According to a post on a non-English site, does 4133 19-26-26 1.5V which sounds like E-die, so may be a rebrand like how 8Gbit Hynix JJR is suspected to be a CJR rebrand. Able to achieve 3866 18-20-20 1.45V by /u/Cyber896 on Skylake, notes that 1.5V made the stick extremely unstable.

4Gbit Rev.F ("F-die")
Relatively new IC, not much is known. Seen in Transcend and Goodram SODIMMs, as well as a 4GB Transcend UDIMM, earliest found ICs having a late 2019 date code. Also seen in multiple G.Skill Aegis sticks (up to 3000 16-18-18), with the 042 code ending in 10F. Stock speeds up to 3200.

8Gbit Rev.B ("B-die")
Characteristics - OC and voltage: CL, RCD and RP all scale from voltage. For everyday use, generally seen doing 3600-4000 14-14-14 around 1.5V. Stability above around 1.5V-1.6V requires restricting how much memory is accessed with maxmem or removemem - in these conditions, b-die is known for benching at 4000+ 12-11-11 with extreme voltage around 1.8-2V.
Characteristics - esoteric: Very finicky and needs maxmem for best settings with high voltage, also needs a lot of retries on some motherboards. Some sticks, especially older ones on A0 PCB, have a temperature sweet spot around 15-20C and need a heater for LN2. Either way, B-die genuinely benefits from a heatsink and airflow. Even water-cooling can provide a marginal benefit.
Some older motherboards, particularly 2-dimm ASUS Z370 and earlier, have trouble doing tight CL on the modern A2 PCB and prefer A0. This can be alleviated by enabling XMP on certain boards. Conversely, A2 is required for very high MHz with A0 starting to struggle (though not outright walling) at 4500Mbps. The A0 PCB was common on G.Skill non-RGB kits even in 2019, though by the end of 2020 even those have switched over to A2.
Found on: 8GB/16GB 3200 14-14-14 and higher MHz settings with similar effective latency (full list here). Corsair ver4.31, except for some review sticks that have been marked ver4.31 but carried C-de (normally ver4.32) instead. NB: B-die found on OEM sticks and low bin sticks identified by marking and not timings is still solid, but tends to be noticeably worse in both performance and voltage scaling than B-die found in "B-die only" bins and isn't worth a premium over Hynix CJR/DJR and Micron 8Gbit E/J/N.
Platform preferences: Best IC for everything so far. Recommended for: Benching on all platforms, though Hynix and Micron have usurped B-die for frequency validation. Suitable for top-end/extreme daily. Used to be considered a bit pricey when mainstream meant 4 cores, but with 8-16 core chips often bottlenecked by dual channel memory B-die makes sense even at a premium.

8Gbit Rev.C ("C-die")
Characteristics: More recent samples seem to scale up to between 1.3 and 1.35V depending on stick. Typical overclock is around 3600 18-20-20, with better sticks hitting 3800. Hits higher frequencies OK, but only given very loose timings. Found on: Corsair ver4.32 3000CL15, 3200CL16, 3600CL18, some G.Skill kits and OEM Samsung sticks.
Platform preferences: Issues reported on X99. Seems to behave well on Intel *lake. Many reports of unstable XMP on AMD.
Recommended for: Perfectly serviceable daily IC in 3200CL16 kits, but no reason to seek it out for OC.

8Gbit Rev.D ("8Gbit D-die")
Characteristics: OEM stick reported to be capable of DDR4-3600 with CL14 at 1.5V, sadly lacking on detail. /u/buildzoid got hold of a stick and has summarised his findings as "if you told me Samsung was packing [Micron] Rev.E and branding it D-die I'd almost believe it based on the timing".
Found on: Samsung sticks; G.skills ending in 8410D (late 2020 and newer; one found sample is a yyww 2049 4x8GB 3200 16-18-18 FlareX kit, another is a 2021 Jan 2x8GB 3600 19-20-20 Rip jaws V set). Corsair modules have been seen under ver4.33 (a yyww 2112 2x8GB 3200 16-18-18 Vengeance LPX kit), too which would imply this revision.

8Gbit Rev.E ("8Gbit E-die")
New IC (late 2020), with minimal overclocking results at this time (one report describes them as C-die but sadder, with worse voltage scaling). Seen in Samsung modules. One user got (presumably) these from Corsair RMA, in a yyww 2113 2400c14 2x8 Corsair Vengeance LPX kit, with a ver4.34.

16Gbit Rev.M ("M-die")
Early planned 16Gbit IC. Seen in OEM modules by Samsung and Adata, and suspected in some 32GB Patriots (a 2x32GB 3600C18 Patriot Viper Steel kit was caught with an 11MJ3 code, suggesting M-die). Voltage scaling is unconfirmed, as while earlier reports suggest there are negative gains past a varying point below 1.35V, Patriot rates what is suspected to be M-die, for 1.35.

16Gbit Rev.A ("A-die")
While seemingly a (much?) newer revision, a quick online scan gave the earliest M-die production unit at yyww 1910, and A-die at 1920. Seen in Samsung modules.

ISSI, Alliance Memory and a bunch of other manufacturers also make, or are suspected to make, DDR4 ICs, but they haven't been seen in consumer sticks.

Manufacturer IC Identification
"Version Number"
Corsair sticks identify the IC with a 'version number' on the label such as "ver4.31" - props to them for this as it helps even less knowledgeable users to match kits when adding more sticks retroactively. The DDR4 numbers aren't officially documented, but they follow the same pattern as DDR3.

The numbers take the "ver X.YZ" format where
* X is IC maker - 3 for Micron/Spectek, 4 for Samsung, 5 for Hynix, 8 for Nanya as with DDR3.
* Y seems to be capacity per rank - 1 for 2GB, 2 for 4GB, 3 for 8GB, 4 for 16GB. Usually this translates directly to IC density (8GB/rank = 8Gbit), but ver4.14 which uses half as many double width "x16" 4Gbit chips is a special case.
* Z is revision, usually starting from A=0 and usually counting up one letter per increment. Hynix's first revisions are lettered "M" which is numbered as X.Y9, Samsung now do this too and it will presumably be the same.
Micron ICs seem to be numbered oddly with different "version numbers" for different JEDEC bins, and different revisions under the same "version number".
The known and possible version numbers are as follows;

3.20Micron4Gbit Rev.APresumed
3.21Micron4Gbit Rev.BConfirmed
3.22Micron4Gbit Rev.E*Speculated
3.22Micron4Gbit Rev.F*Confirmed
3.31Micron8Gbit Rev.BConfirmed
3.31Micron8Gbit Rev.DPresumed
3.31Micron8Gbit Rev.EConfirmed
3.32Micron8Gbit Rev.HConfirmed
3.32Micron??????????wk27 '17 2x8GB 2666 16-18-18-36 1.2V
3.32Micron??????????wk46 '19 2x8GB 3000 15-17-17-35 1.35V
3.40Micron16Gbit Rev.B (2133 bin)Confirmed
3.41Micron??????????wk44 '20 2x16GB 3600 18-22-22-42 1.35V
3.43Micron??????????wk43 '20 2x16GB 3200 16-19-19-36 1.35V
3.43Micron16Gbit Rev.E??? (or bad bin Rev.B)wk51 '20 2x16GB 3200 16-20-20-38 1.35V
3.44Micron16Gbit Rev.B (2666 bin)Confirmed
4.14Samsung4Gbit D-die (4x16)Confirmed
4.23Samsung4Gbit D-dieConfirmed
4.24Samsung4Gbit E-dieConfirmed
4.21Samsung8Gbit B-die (4x16)Presumed
4.31Samsung8Gbit B-dieConfirmed
4.31Samsung8Gbit C-die**Presumed
4.32Samsung8Gbit C-dieConfirmed
4.33Samsung8Gbit D-diePresumed
4.34Samsung8Gbit E-diePresumed
4.49Samsung16Gbit M-diePresumed
4.40Samsung16Gbit A-dieSpeculated
5.29Hynix4Gbit MFRConfirmed
5.20Hynix4Gbit AFRConfirmed
5.21Hynix4Gbit BJRSpeculated
5.22Hynix4Gbit CJRPresumed
5.39Hynix8Gbit MFRConfirmed
5.30Hynix8Gbit AFRConfirmed
5.31Hynix8Gbit "BFR"???Speculated
5.32Hynix8Gbit CJRConfirmed
5.33Hynix8Gbit DJRPresumed
5.38Hynix8Gbit JJRPresumed
5.49Hynix16Gbit MJRPresumed
8.20Nanya4Gbit Rev.ASpeculated
8.21Nanya4Gbit Rev.B***Presumed
8.23Nanya4Gbit Rev.D***Presumed
8.30Nanya8Gbit Rev.APresumed
8.31Nanya8Gbit Rev.B****Confirmed

Especially with Micron, Corsair version numbers are sometimes weird. Confirmed means an IC has been seen under a version number, not that it can't also cover something else.

*Rev.F is confirmed to come in ver3.22 sticks, but that doesn't leave a gap for Rev.E. It's wildly guessed that they may both appear under 3.22.
**Techpowerup recently got a sample kit of Vengeance RGB Pro SL 2x8GB 3600c18 under this version; however, the chips had SAC marks on them (which by Corsair's IC labeling scheme would indicate C-die) and behaved like C-die in OCing.
***Version number seen in the wild, IC unconfirmed.
****Deduced from the NAB... Corsair code on the ICs, as well as a Corsair rep statement, acc. to one post from China.
Date code
The first 4 digits of a Corsair serial number are a date code in the form yyww, eg 1528 is week 28 2015.
Corsair relabeled ICs
Some ICs loaded into Corsair sticks have been shown to assume a marking with a Corsair logo and two text lines, the first presumably stating the IC configuration, and the second featuring an internal Corsair code that seems to correspond to the IC manufacturer and stepping, as well as a yyww format date at the end. Unfortunately, such kind of marking has only been confirmed in some ver5.xx (Hynix) and 8.xx (Nanya) sticks. Samsung's (ver4.xx) may have it too but as seen in the ver4.31 example, it may collide with the version number scheme.

VersionCodeICOriginal partial mark
4.31SAC...Samsung 8Gbit C-dienone, determined by OCing behaviour
5.20HYA...Hynix 4Gbit AFRDWMF...
5.30HYA...Hynix 8Gbit AFRDTCC...
5.32HYC...Hynix 8Gbit CJRDTBM... / none
- (ValueSelect)NAA...Nanya 8Gbit A-die?arbitrary Nanya
8.31NAB...Nanya 8Gbit B-die?arbitrary Nanya


Well-known member
Jul 30, 2015
or you could link the reddit post


Jul 13, 2015
Part 2 -Re-edit

G.Skill SN table
The relationship between G.skill's SNs and IC used seems known as long as a code starting with 042/T42/043 is present on the stickers; however, it has seemingly only started showing up on G.skills in Aug 2017, meaning older stuff doesn't have as streamlined a classification... but here's hoping there is one.
Some of the sticks are pictures grabbed from Ebay and elsewhere, others are submitted by users.
042/T42/043/etc. code current theory
By this theory, every DDR4 G.skill stick produced in or after Aug 2017 features a code on its sticker, of this or very similar (first 3 characters differ) form:
The last five characters here are what matters the most, with
X standing for the die density: 4 for 4Gbit, 8 for 8Gbit, S for 16Gbit;
I being a fixed number, 4/8/6, sometimes pertaining to DRAM width (x4/x8/x16 respectively) but not always (8410C and 8810C sticks are identical under the hood);
Y standing for the IC manufacturer: 1 for Samsung, 2 for Hynix (some fully marked, some rebranded - possibly eTT), 3 for Spectek/Micron, 4 for Powerchip (PSC), 5 for Nanya, 9 for JHICC;
J being some number, purpose unknown but could be related to binning:
for 3xx, one theory suggests (and seems to work) that 30x stands for D9 type Microns, 31x for C9s, and 33x for Spectek ICs;
Z standing for the DRAM stepping.
...48211 - 4Gbit 1JR? DTBM partials agree, but then
...48209 (?) - ???
...4821 (sic!) - ???
...88211 - 16Gbit AJR cut down to 8Gbit (DTBU partials)
...8833A - 8Gbit Rev.A in a 3000C16 kit?
...4833A - could be 4Gbit Rev.A (2400 flat 15 sticks)
...4833B - could be 4Gbit Rev.B (2133 flat 15 sticks)
...48309 - ???
...3xC - C-grade?
...4897A - seen in a post originating from China, SPD reportedly says Hynix, later determined to be JHICC 4Gbit based on the partial mark
G.skill DDR4 products sold in China seem to feature a T42 code instead, and some sticks start with L42, A42 or 043 for an unknown reason.
New markings (old)
KitDateSNOther markingsICDetermined by
4x16GB Ripjaws V F4-2666C15Q-64GVR 1.2VOct 201919404292281"04266X8810C" between barcode and warranty warningsuspect 8Gbit Samsung C-dieseen on Ebay
2x8GB TridentZ Royal F4-4800C18D-16GTRS 1.5VAug 201919313319009 and -010"0421308810B" above barcode8Gbit Samsung B-dieIC label under HS, OC characteristics
2x16GB Sniper X F4-3600C19D-32GSXKBJun 201919262719091 and -092"04266X8820J" between barcode and warranty warning8Gbit, probably Hynix, suspect JJR?seen on ebay
2x16GB Flare X F4-2400C15D-32GFXMay 201919202078223 and -224"04240R8821A" above barcodeTheory suggests AFR?seen on Ebay
4x4GB Ripjaws 4 F4-2666C16Q-16GRB 1.2VFeb 201919080825559 etc"04240H48211" above barcode4Gbit ?????seen on Ebay
2x16GB Ripjaws V F4-3000C16-16GVRBJan 201919040503367 and -368"04213T8821A" between barcode and warranty warning8Gbit, probably Hynix, maybe CJRThaiphoon, but the reported part number may be wrong
4x8GB Ripjaws 4 F4-2666C15Q-32GRR 1.2VJan 201919020188252 etc"04240X8820M" above barcode?8Gbit MFR in 2019???seen on Ebay
2x4GB Ripjaws V F4-2400C15D-8GVRDec 201818514655259"04240H4833A" between barcode and warranty warning4Gbit ?????seen on Ebay
2x8GB 3200C161846-04240X8820CAFR???SPD says AFR but may be wrong
2x8GB FlareX F4-2400C15D-16GFXNov 201818453949935 and -936"04240R8823A" above barcode8Gbit Hynix AFRThaiphoon
2x8GB 3600C181844-04213X8821CCJRThaiphoon, XMP
2x8GB TridentZ F4-4133C19D-16GTZSWCOct 201818433674675 and -676"0421308810B" above barcode8Gbit Samsung B-dieXMP and thaiphoon report
1x8GB Ripjaws V F4-3600C19S-8GVRBOct 201818423547175"04213X8821C" between barcode and warranty warning8Gbit Hynix CJRThaiphoon Burner SPD report
1x8GB Ripjaws V F4-3600C19S-8GVRBOct 201818423547162"04213X8821C" between barcode and warranty warning8Gbit Hynix CJRThaiphoon Burner SPD report
1x8GB Aegis F43000C16S-8GISB 3000 16-18-18-38Oct 201818403351340"04213X8821A" above barcode8Gbit Hynix AFRThaiphoon
2x4GB Ripjaws 4 2666 F4-2666C15D-8GRR 1.2VOct 201818403335611"04240X4810D" above barcodecould be anything 4Gbit, but theory suggests 4Gbit D-dieseen on ebay
4x8GB 2666 F4-2666C15Q-32GRRSept 201818383149485 etc04213X8821CSPD says MFR, POSTing 3600 16-19-19 says CJRThaiphoon, testing
2x8GB TridentZ RGB F4-4266C19D-16GTZRJul 201818271991539 and -240"04213X8810B" above barcode8Gbit Samsung B-dieXMP and Thaiphoon
2x8GB Flare X 3200C14Apr 201818171206284"04213X8810B" above barcode8Gbit Samsung B-die3200C14 XMP
2x8GB Ripjaws SO-DIMM F4-2400C16D-16GRSFeb 201818070441495 and -496"04240X8810C" above barcode8Gbit Samsung C-dieICs visible (no HS)
4x4GB TridentZ F4-3866C18Q-16GTZ 3866 18-22-22-42Jan 201818040220633 etc"04213X4810E" above barcode4Gbit Samsung E-dieXMP and Thaiphoon
2x8GB TridentZ RGB F4-3200C16D-16GTZKWDec 201717522049211 and -212"04213X8821M" above barcodecould be anything, but theory suggests 8Gbit Hynix MFRseen on Ebay
2x4GB TridentZ F4-3000C15D-8GTZB 3000 15-16-16-35Dec 201717501936003 and -004"04213X4810E" above barcode4Gbit E-dietested by owner
2x8GB Ripjaws4 F4-3000C15D-16GRBB 3000 15-16-16-35Dec 201717501913583 and -584"04240M8810B" above barcode8Gbit Samsung B-dieseen on Ebay, asserted by seller
2x4GB Ripjaws4 F4-2800C16D-8GRR 2800 16-16-16-36Nov 201717461509870"04213X4810E" above barcode??????seen on Ebay
2x8GB TridentZ RGB F4-2400C15D-16GTZRNov 201717451458406"04213X8821M" above barcodecould be anything, but theory suggests 8Gbit Hynix MFRseen on Ebay
2x4GB RipjawsV F4-2400C15D-8GVRNov 201717451434261"04213X4820A" between barcode and warranty warningtheory suggests 4Gbit AFRseen on Ebay
1x16GB RipjawsV F4-3200C16S-16GVKOct 201717410985060"04213X8810B" between barcode and warranty warningSame marking as B-die?seen on Ebay
2x8GB Flare X F4-2400C16D-16GFXAug 201717340143621 and -622"04240H4833A" above barcode?????seen on Ebay
New markings - "042 code" table (old)
The IC seems to be indicated by a code starting in 042. So far the same code hasn't been seen on sticks with different ICs. This table should hopefully clarify the theory, but is based on the known information as above.
CodeRanksDensityManufacturerRevisionKits seen onKits confirmed on
04240X8820COne8GbitHynix?SPD says A?1?/1
04240X8820MOne8Gbit?Hynix??MFR in 2019??10/1
04213T8821AOne8GbitHynix?SPD says C???1?/1
04213X4820AOne4GbitHynix?A (AFR)?10/1
04213X8821COne8GbitHynixC (CJR)43/4
04213X8821AOne8GbitHynixA (AFR)11/1
04213X8821MOne?8Gbit?Hynix?M? (MFR)20/2
*Who on earth makes 4Gbit Rev.A in late 2018? Nanya....? Code also seen on August 2017 DR kit.
**I guess the code is for IC and doesn't care for ranks
***8Gbit JJR is in fact a thing that exists, so this isn't as odd as it sounds.
Old markings
Seems to be the same as DDR3?
KitDateSNOther markingsICDetermined by
2x8GB TridentZ F4-3200C16D-16GTZBJul 20171730B4002294517 and -518-????seen on Ebay, settings could be nearly anything
2x8GB RipjawsV F4-2400C15D-16GVRMay 20171721B6001511013 and -014"888" in top-left corner????seen on Ebay, settings could be anything
2x16GB TridentZ F4-3200C15D-32GTZKWJan 20171704A5000233673 and -674-8Gbit Samsung B-die3200 15-15-15 XMP
2x8GB TridentZ F4-3200C16D-16GTZBNov 20161646A4004719693-????seen on ebay, settings could be nearly anything
2x8GB Ripjaws V 3000 15-15-15-35Nov 20161645A5004672693-Probably Samsung? B or DR E3000 15-15-15 would be a damn strong bin of Hynix.
2x8GB Ripjaws V 2400 15-15-15-35Nov 20161645A5004672787 and -788-????seen on Ebay, settings could be anything
2x16GB Ripjaws SO-DIMM F4-2133C15D-32GRSOct 20161643A4004396979 and -980-8Gbit somethingseen on Ebay, settings could be anything
* First 4 digits of S/N seem to be date and week as with DDR3
* Seems to have been a change where the second code was introduced - old sticks follow the same S/N pattern as DDR3
* This "04213X" code looks promising - maybe the next two digits of 88 is density and number of chips, then 10 for Sammy and 21 for Hynix, then B/C for revision? * All the RAM from week 43 2018 and later seems to use a different code?
Patriot are relatively consistent with IC per model and don't yet have a known SN pattern have a pattern of sticker codes to the right from the barcode which is not always reliable. They've also been seen changing timing specs within the same part number in order to use different ICs (e.g. 3733 17-19-19 -> 3733 17-21-21).
Patriot sticker codes
This section would be impossible without the awesome prior research by Reous and others over at Ryzen RAM OC Community. See here.
The perpendicular code to the right from the barcode, which is sometimes repeated on the product box, usually assumes the following form: 11BF1 where
11 = manufacturer (Samsung in this case)
B = die stepping (usually)
F = die density (C for 4Gbit, F for 8Gbit, J for 16Gbit)
Such scheme appeared in Patriot sticks some time in 2017. Earlier units omitted the die density character (e.g. 11B1).
Bare JEDEC spec sticks w/o heatspreaders do not feature this code.
This full table only includes sticks found in the wild, store listings, or review pictures. Select common specimens are presented below.
0BCFHynix8Gbit CJR
0BDFHynix8Gbit DJR
0BMJHynix16Gbit MJR
0BAJHynix16Gbit AJR
11B1Samsung8Gbit B-die
11BFSamsung8Gbit B-die
11D1Samsung4Gbit D-die
Patriot rebranded IC markings

Line 1Line 2Line 3Suspected ICSuspected forImage link
PATRIOTPM1G8D4BU-0751935BC36248Gbit Hynix DJR??4400 18-21-21-42 1.5V, SPD says Hynixone, two
PATRIOTPM1G8D4BU-0752008BD36548Gbit Hynix DJRDTDR partial says DJRone
PM = Patriot Memory
1G8 = 1Gbit deep, 8 bits wide
D4 = DDR4???
BU = ???????????
-075 = JEDEC speed bin (0.75ns cycle time, DDR4-2666)
1935BC3624, 2008BD3654 - 1935, 2008 are highly likely to be yyww
Spectek relabeled ICs (under construction)
An example relabelled Micron IC is:
F 1744

083E seems to be the Micron JEDEC bin, F seems to be the revision the letter F has been seen on 16Gbit density stuff that definitely isn't Revision F so it's unclear what it is, and 1744 is speculated to be the production week (yyww).
Hynix partial markings
Some Hynix ICs have a minimal/partial marking (newer units with a QR code in the top right) as a code along the bottom edge such as DTBM08310M1. These may still be visible when the markings have otherwise been sanded off in order to rebrand an IC, or when the chips were shipped only partially marked to module assemblers (eTT?). These codes can tell you what the IC is:
First 4 charactersIC
DTBM8Gbit CJR (incl. downbins)
DTBU/DWBU16Gbit AJR (incl. downbins)
DT7D16Gbit CJR
Some marks start with an N instead of a D, which indicates 96-ball x16 ICs. There are also some which start with a B (BTS4 seen in an Apacer kit, BME4 in some Corsair, both 8Gbit) but the revisions standing behind are yet to be confirmed.
*As of late 2020, only seen on suspicious OEM "Hynixes" with a non-original Hynix sticker, an "AKRS" sticker, and high reported failure rates, sold in Russia/CIS. Mark carried over from 4Gbit DDR3L BFR and shared between different proposed "revisions", from 4Gbit MFR to 16Gbit CMR, which is very sketchy.
Memory PCB can affect overclocking characteristics and compatibility. Presented here is a list of standard PCB layouts and what is known about them.
Please note: there is a lot of confusion about what is A0 and what is A1, with a lot of people incorrectly referring to A0 PCBs as A1. Keep in mind that PCB information reported in Thaiphoon Burner or other SPD reporting tools may not be accurate as it relies on the SPD being programmed correctly.
Single Rank (single-sided) with standard ICs
A0 is the original single rank layout designed for JEDEC (stock) speeds up to DDR4-2133. It can be identified by having 8 normal ICs on one side that are rougly evenly spaced, with the SPD chip right in the middle if you're peeking under a heatspreader from the contacts side.
A0 PCB is also known as the "non-RGB PCB" as it's used on G.Skill non-RGB single rank kits up to DDR4-4266 (and older, now-discontinued non-RGB 4266+ kits). People often mistakenly call this PCB "A1", to the point that if you see an overclocker talk about "A1 PCB" they probably mean A0.
This is the best PCB for running extreme b-die profiles/presets aimed at 4000-4133 12-12-12 or 12-11-11. Not because it's a better PCB, but because it has better compatibility with 2-DIMM boards.
A1 is designed for JEDEC (stock) speeds up to DDR4-2400, and is shared with the ECC D1 PCB. This means that on non-ECC modules you will see an empty pad for a 9th IC. This is normal and part of the design; it does not mean the PCB is being used improperly.
Compatibility is a bit of an unknown as vendors popular with overclockers don't use this PCB, but it has been tested with 4Gbit Samsung E-die from OEM kits and Crucial Ballistix and is certainly capable of at least DDR4-4266 CL19.
Identifying A1 vs A2
A1 looks similar to A2 under the heatspreaders - the ICs are in two groups, one on each side. There are a few 'tells':
  • A1 has the SPD chip on the front, next to an IC, and no components on the back. A2 has the SPD chip and some smd components on the back.
  • Both A1 and A2 have a single SMD capacitor by the notch. On A1 the edge of this is pretty much lined up with the edge of the notch, on A2 it's offset by a good 1-2mm.
  • A1 has unpopulated pads for SMD conponents supporting the 9th IC along the bottom edge that may be visible between the heatspreader and contacts.
A2, also known as the "RGB PCB" as G.Skill use it on their RGB kits as well as more recent (at time of writing - early May 2019) non-RGB >4266 kits, is the latest (as of early May 2019) standard single rank PCB layout and is targeted at JEDEC (stock) speeds up to DDR4-2666. It's a very good PCB that's sadly best known for compatibility issues with 2-DIMM socket 1151 boards, especially the Asus Apex series - on which it needs CL of 19 or above for DDR4-3866+.
It should be stressed that problems doing tight timings on the A2 PCB are about compatibility not quality - on 4-DIMM socket 1151 boards it works great. If you're trying to do really extreme settings on A2-based B-die and having trouble, making sure XMP is enabled will often alleviate the problems. You should also look for a more recent bios that may improve compatibility.
A2 is identifiable by having all the ICs crammed tightly into two clusters, one on each side. The gap between the clusters is huge - about as big as the width of a cluster. If you're not sure which single rank 8-chip PCB you have, check the section above on A1 vs A2.
Dual Rank (double-sided) with standard ICs
B0, B1 and B2 exist for JEDEC (stock) speeds of <=2133, <=2400 and <=2666 respectively.
B0 looks like a dual rank version of A0
B1 looks like a dual rank version of A2 (though it predates A2 - it might be more accurate to call A2 a single rank version of B1)
B2 presumably would look like a dual rank version of A3.
Note: There is no dual rank version of A1 in the B-series.
Single Rank (single-sided) with double-width "x16" ICs
C0 is the only PCB for this layout, designed for JEDEC (stock) speeds <=DDR4-2400.
Dual Rank (single-sided) with double-width "x16" ICs
F0 is a PCB layout designed by Avant Technology for JEDEC (stock) speeds up to DDR4-2666 with dual rank x16 ICs, a pretty barmy configuration but one that has been seen in the wild. It's a double-sided PCB and in testing a Corsair "ver4.14" kit with 4Gbit (256Mx16) Samsung D-die ICs clocked similarly to a conventional dual rank 4Gbit E-die kit, both hitting a wall on an Asus Maximus IX Apex at DDR4-3466. Timings tightened as expected for D-die so there's no obvious massive quirk.

Last revised by HowDoIMathThough - 2 years ago