Z790 DDR5 7600 XMP Problems

amehmetbeyoglu

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Oct 23, 2017
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Hey there,

I have just configured a new system

* Carbon Z790 Wifi DDR5 MB,
* i9 13900KF
* G.SKILL 7600MHz CL36 1.40V RGB RAMS (F5-7600J3646G16GX2-TZ5RK / 136095)

My problem is when I enable XMP it detects the RAMs correctly as labeled (7600, CL36, 1.4V etc.) but the system is not stable, Windows (10 64bit) goes to blue screen.
for now I am running the RAMs at a lower frq, 7200MHz may or may not work, but sub 7000 frq's are more stable and looks OK.

MB Specs states that 7600+OC is supported but it is not in the QVL list. (G.skill upto 7200Mhz.) But as you see the MB specs suggests on the front page it will support 7600+ with OC. I am confused.

What can I do to get the rated performance out of the system or is it this all just a lotary and I am not the lucky guy or is it just fooling with the specs?

Note: MB Firmware is up-to-date.
 
DDR5-7600 is around the absolute top end of what is currently possible even on Z790/13th gen. That is with a flagship board model and a very good IMC (integrated memory controller) in your CPU. Because the IMC quality is just another silicon lottery, just like the quality of the normal cores. So this DDR5-7600 what experienced RAM overclockers using a CPU with a known good IMC can stabilize, if everything goes well. But i've also recently read a review of the EVGA Z790 CLASSIFIED where the maximum stable speed was DDR5-6800, using all the tricks in the book. So it depends on everything working well together, including the BIOS and its settings. Even just DDR5-7200 can be difficult to make stable, it takes the right BIOS settings to make it work, like you can see in this video.

What you have to keep in mind is: XMP is never a guarantee, it's only a goal that can be reached in optimal conditions. So about the RAM speed that's on the packaging, you can buy RAM with whatever advertised speed that you want, but that only means that the RAM itself is capable of it. However, the following factors all affect if the RAM can run at a certain speed:

1) The mainboard model (PCB layer count, PCB trace optimization, RAM slot topology and slot count, component selection, RAM VRM etc.)
2) The mainboard's BIOS optimizations and the BIOS settings
3) Your CPU's integrated memory controller (IMC), quality depends on the individual CPU (silicon lottery)
4) The properties of the RAM modules.

So the RAM is just one piece of the puzzle in the memory system. If someone from the future brought back a kit of DDR5-8800, will it run at DDR5-8800 in any current hardware? Of course not. But the RAM itself is not the limitation. The board, BIOS and IMC are not capable of it at the moment, such speeds would require future platforms.

DDR5-7600 is simply at the edge right now, you definitely need to know what you're doing to get it stable. This is not some "plug & play" speed, this is something that enthusiasts buy to have the best potential on the RAM side (highly binned kit), and then do a back and forth of fine-tuning in the BIOS and stress-testing.


You can compare it to the early days of DDR4. For a long time the speed to get was DDR4-2666, then the platforms (boards/CPUs) became better, the RAM itself became better, and the sweet spot first became DDR4-3200, then later on it became DDR4-3600. Until this day, you can see that the most commonly sold kits are DDR4-3200 or -3600.

However, with you getting DDR5-7600 at this point of DDR5 development, it's similar to a time where everyone was only getting DDR4-2666, but you're suddenly getting one of the first high-end DDR4-3600 kits that became available. It's a similar sort of jump, from what is known to be fast enough and unproblematic at the time, to something completely enthusiast-grade that probably needs manual adjustments to work. At the moment, people are buying something like DDR5-5200/5600/6000. If they're a bit more adventurous, they may get DDR4-6200/6400 or so. But the DDR5-7xxx range is still reserved for those who really know how to handle high-speed DDR5 and don't shy away from tinkering with all the related settings in the BIOS.

Getting a high-spec kit of RAM to work 100% stable is like fine-tuning a race car by driving on a circuit. You need to drive a bit, come into the pits/garages for some feedback, adjust accordingly, and drive out again for more testing. No BIOS can automatically do that for you. The automatic settings only work for road cars, not for race cars. If you don't know how to make this work (and indeed it might also be impossible with your specific CPU's IMC), then this kit might've been a bit of a waste of money, because you would have to run it at DDR5-6xxx to stabilize the memory system.
 
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I have been through this on the Carbon and can't get above 6800 stable and have tried every stable and beta bios I can find. Here are some timings you can try for better memory testing that might work for you.
msicarbonz790yctmbest~2.png
 
I bought MSI Z790 Carbon+14900KF and my T-Force FF3D532G7600HC36DDC01 is in QVL list!
But it wont work on X.M.P. 7600. My memory is stable only when it comes 7000 Mhz 34-42-42-54.
I've read enough similar posts about this issue and I think this 8-pcb layer board is crap. Dont buy that mobo unless MSI upload any fix (if they do that).

 
Also see my previous reply. DDR5-7600 is firmly in the enthusiast range. If you don't have deep knowledge on how to stabilize such a high and demanding XMP speed, don't even bother buying this kind of kit, it will almost never work out of the box. It doesn't matter much that it's on the QVL, this is a speed that needs manual tuning to work. If it works at all, because at this level, it also highly depends on how good your CPU's IMC is (integrated memory controller).

If we look at the board's specifications, that's what they list there as the maximum:

Screenshot 2024-01-28 at 19-53-44 MPG Z790 CARBON WIFI.png


If you know anything about those specs, like i also write in my RAM thread, you will know that they are usually what their in-house RAM overclockers have achieved with hand-picked modules and custom RAM settings, on a CPU with a very good IMC. So even in their in-house testing, where they have several very capable overclockers under contract, they cannot really get much higher than DDR5-7600 with two single-rank modules (all the RAM world records are done with a single module only).

Here you can watch a video that explains why the QVL is pretty much useless when it comes to enthusiast-grade speeds:



Here is the RAM manufacturer's QVL from G.Skill for a similar kit than yours, F5-7600J3646G16GX2-TZ5RK:

Screenshot 2024-01-28 at 20-19-37 F5-7600J3646G16GX2-TZ5RK - QVL - G.SKILL International Enter...png


For MSI, they only list the MPG Z790I EDGE WIFI, which when you look at the board, the reason may become clear immediately: It only uses two DIMM slots, which results in a much cleaner signal quality. For other brands, only their high-end models (ASUS ROG MAXIMUS) or even just the top model is listed.

If we then look at a DDR5-7200 kit like the F5-7200J3445G16GX2-TZ5RK, then most of the other MSI Z790 boards appear (apart from the really cheap ones like Z790-S, Z790-P and such):

Screenshot 2024-01-28 at 20-25-49 F5-7200J3445G16GX2-TZ5RK - QVL - G.SKILL International Enter...png


Then with a DDR5-6600 kit, even those cheap Z790 boards appear. This is much more in line with reality than the board manufacturers' QVL.
 
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So, you say the meaning of QVL list on MSI MAG Z790 Carbon page: the memory can work at jedec. LMAO. Thanks!
Next time MSI can get their motherboards and put It in their ...
 
This is similar for all motherboards when it comes to enthusiast-grade XMP speeds like DDR5-7600. The motherboard brands' QVL at that speed level is mostly for bragging about what can be achieved if your CPU's IMC is really top notch. If your CPU's IMC is not top notch, you will not get this working, and this fact is generally understood by the RAM enthusiasts. But for many other people, they don't realize it, or only when it doesn't want to work.

This is just the usual marketing stuff that is so easy to fall for. Higher numbers look better. And motherboards are partly sold by what numbers can be achieved in the RAM department.

The RAM makers, they don't have to make a "marketing QVL" like the board makers, because they guarantee that their RAM kits can do the speed in isolation. Meaning, once you have a board that is good enough, and especially once you have a CPU with an IMC that is good enough, then the RAM kit itself won't hold you back from reaching the XMP. Because the RAM kit was binned for this speed, and most of the time a different part of the memory system will be the limiting factor, not the RAM modules. So, with this in mind, they can release more truthful QVLs of what speed actually tends to run on which board, like what G.Skill is doing on their site. Once you go to DDR5-7600, only the high-end board models will even be good enough for it, let alone most CPUs' IMCs.

MSI boards are not particularly worse or better than other brands when it comes to enthusiast-grade XMPs. And other board brands play exactly the same game with their QVLs. It's up to the buyer to develop some understanding of what speeds are actually "safe high speeds" / "plug & play", what speeds are getting up there, and what speeds are total enthusiast speeds which need a really good IMC, good board, and perhaps tweaking some voltages etc. to work.
 
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