Can someone explain in simple terms whether I need or should enable AMD EXPO?

mortar_user_64GB

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I'm preparing for a first pc build (my former PCs have been prebuilt) and have gone with an MSI Mortar B650 with a 7950x and 64gb Kingston Fury Beast Ram 6000. I just want to know if I need to enable EXPO and if so why? What exactly does EXPO do? I've heard (though not investigated) that EXPO has caused issues or something (CPU overvolting?), specifically with the X3D CPUs, but that the extent of my awareness. Any advice of info would be appreciated.
 

ryegrass

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I'm preparing for a first pc build (my former PCs have been prebuilt) and have gone with an MSI Mortar B650 with a 7950x and 64gb Kingston Fury Beast Ram 6000. I just want to know if I need to enable EXPO and if so why? What exactly does EXPO do? I've heard (though not investigated) that EXPO has caused issues or something (CPU overvolting?), specifically with the X3D CPUs, but that the extent of my awareness. Any advice of info would be appreciated.
EXPO basically makes the RAM run faster, since almost everything the computer does uses RAM, making the RAM faster makes the computer faster. In order to do that certain voltages to the RAM and the memory controller (which is in the CPU) need to be increased. Unfortunately, some voltages to the CPU were originally too high resulting in a few CPUs being damaged. This has been fixed in the latest bios.
 
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citay

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Yes, what ryegrass said. XMP as well as EXPO lift the RAM speed (and thus its performance, which also improves overall system performance) beyond the baseline speed that you get without it.

There are also kits that don't have an XMP/EXPO profile, from Kingston such a kit would be the Kingston FURY Beast Kit 32GB, DDR5-4800, CL38-38-38 (KF548C38BBK2-32). But this kind of RAM is mostly used for office PCs and such, where performance isn't crucial. For a PC with a 7950X, which tells me you're gonna have a lot of demanding, highly multithreaded workloads (otherwise, why would you go for that CPU model), using DDR5-4800 RAM with slow timings would create a bottleneck for CPU performance. DDR5 gets most of its performance advantage over DDR4 when high frequencies are being used (to make up for its higher latencies), so DDR5-4800 with slow timings will often perform worse than good DDR4, making it pointless.

That's why you aim for higher DDR5 speeds such as DDR5-6000 with decent timings, which should already be superior to a lot of DDR4 configurations. And to reach that speed, you need a bit higher voltage, and that is all bundled together in an XMP (Intel) or EXPO (AMD) profile.

Note that XMP or EXPO only tell the BIOS to increase the DRAM Voltage to a certain value, not some other voltages that affect the CPU. The latter is done by the BIOS itself, because it knows it also needs higher voltages for the memory controller inside the CPU to reach certain RAM speeds. And previously, the board makers were too generous with the voltage increase there, which could actually kill certain CPUs. This has now been curtailed a bit on AMD boards.
 

mortar_user_64GB

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Thank you.

Is it odd, because EXPO affects RAM speed by upping voltage supplied to RAM alone, that this would have a knock on effect of roasting the CPU? - seems like RAM and CPU voltage would/should be on different power circuits - i.e controlling them should be different operations.

As to my initial question though, from what I gather, turning on EXPO should be required if the RAM is EXPO-rated, because by turning on EXPO you will get the speeds advertised/paid for - is this correct?
 

mortar_user_64GB

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Yes, what ryegrass said. XMP as well as EXPO lift the RAM speed (and thus its performance, which also improves overall system performance) beyond the baseline speed that you get without it.

There are also kits that don't have an XMP/EXPO profile, from Kingston such a kit would be the Kingston FURY Beast Kit 32GB, DDR5-4800, CL38-38-38 (KF548C38BBK2-32). But this kind of RAM is mostly used for office PCs and such, where performance isn't crucial. For a PC with a 7950X, which tells me you're gonna have a lot of demanding, highly multithreaded workloads (otherwise, why would you go for that CPU model), using DDR5-4800 RAM with slow timings would create a bottleneck for CPU performance. DDR5 gets most of its performance advantage over DDR4 when high frequencies are being used (to make up for its higher latencies), so DDR5-4800 with slow timings will often perform worse than good DDR4, making it pointless.

That's why you aim for higher DDR5 speeds such as DDR5-6000 with decent timings, which should already be superior to a lot of DDR4 configurations. And to reach that speed, you need a bit higher voltage, and that is all bundled together in an XMP (Intel) or EXPO (AMD) profile.

Note that XMP or EXPO only tell the BIOS to increase the DRAM Voltage to a certain value, not some other voltages that affect the CPU. The latter is done by the BIOS itself, because it knows it also needs higher voltages for the memory controller inside the CPU to reach certain RAM speeds. And previously, the board makers were too generous with the voltage increase there, which could actually kill certain CPUs. This has now been curtailed a bit on AMD boards.
Thank you.

Is it odd, because EXPO affects RAM speed by upping voltage supplied to RAM alone, that this would have a knock on effect of roasting the CPU? - seems like RAM and CPU voltage would/should be on different power circuits - i.e controlling them should be different operations.

As to my initial question though, from what I gather, turning on EXPO should be required if the RAM is EXPO-rated, because by turning on EXPO you will get the speeds advertised/paid for - is this correct?
 

mortar_user_64GB

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EXPO basically makes the RAM run faster, since almost everything the computer does uses RAM, making the RAM faster makes the computer faster. In order to do that certain voltages to the RAM and the memory controller (which is in the CPU) need to be increased. Unfortunately, some voltages to the CPU were originally too high resulting in a few CPUs being damaged. This has been fixed in the latest bios.
Interesting that to reach the RAM speeds advertised I have to turn EXPO on, which effectively overclocks/ups the voltage supplied to the RAM. As a novice I would have assumed a 6000MT/s RAM stick would perform as advertised without essentially needing to overclock it.
 

citay

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Is it odd, because EXPO affects RAM speed by upping voltage supplied to RAM alone, that this would have a knock on effect of roasting the CPU? - seems like RAM and CPU voltage would/should be on different power circuits - i.e controlling them should be different operations.
Like i mentioned, the RAM profile (XMP/EXPO) traditionally only dictates the RAM Voltage. The other voltages are not raised by what's in the profile, they are raised because the motherboard's BIOS is programmed to raise certain voltages for certain RAM speeds. Any time you run at higher frequencies, you need more voltage than at lower frequencies. This also applies to the CPU's memory controller. The CPU has certain regions with different voltage requirements. CPU core voltage (VCore) is only for the actual CPU cores, and is usually not influenced by the RAM speed. But then you have the "uncore"/SoC region, which houses things like the IMC (integrated memory controller), and that region needs more voltage, the higher the RAM speed.

But the board makers tend to be very generous when raising those uncore voltages, prioritizing stability over power draw/efficiency/longevity. Meaning, they raise the voltage more than necessary, just to be on the safe side in some edge cases and get less customer complaints. Turns out, sometimes the voltage is raised so much that it can cause damage. So this voltage increase with higher RAM speeds needs to be tuned better to avoid this. For AMD this has mostly been done now (by capping some voltage at a certain level). For Intel not. However, no CPUs are dying with Intel, so they don't see a need there.

Also worth a watch:


As to my initial question though, from what I gather, turning on EXPO should be required if the RAM is EXPO-rated, because by turning on EXPO you will get the speeds advertised/paid for - is this correct?
Yes. If you don't plan on using XMP or EXPO, then there is no need to get a more expensive kit of DDR5-6000 or so. You might as well get a cheaper kit of DDR5-4800 without XMP/EXPO, because that's exactly what the pricier kit would run at, should you not enable EXPO.

As a novice I would have assumed a 6000MT/s RAM stick would perform as advertised without essentially needing to overclock it.
Well, but that's a wrong assumption. All RAM will first boot at a safe JEDEC speed, these are the non-XMP/EXPO speeds of DDR5-4800, -5200, -5600. Most of the time you will see it boot at DDR5-4800 because that will be the basic profile that the RAM offers. This is done so that it can boot in all boards, with all CPUs. If it was set at DDR5-6000 right from the get-go, some configurations couldn't support it, so you couldn't even boot the system like that. Hence the extra step of enabling the profile.
 

mortar_user_64GB

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Like i mentioned, the RAM profile (XMP/EXPO) traditionally only dictates the RAM Voltage. The other voltages are not raised by what's in the profile, they are raised because the motherboard's BIOS is programmed to raise certain voltages for certain RAM speeds. Any time you run at higher frequencies, you need more voltage than at lower frequencies. This also applies to the CPU's memory controller. The CPU has certain regions with different voltage requirements. CPU core voltage (VCore) is only for the actual CPU cores, and is usually not influenced by the RAM speed. But then you have the "uncore"/SoC region, which houses things like the IMC (integrated memory controller), and that region needs more voltage, the higher the RAM speed.

But the board makers tend to be very generous when raising those uncore voltages, prioritizing stability over power draw/efficiency/longevity. Meaning, they raise the voltage more than necessary, just to be on the safe side in some edge cases and get less customer complaints. Turns out, sometimes the voltage is raised so much that it can cause damage. So this voltage increase with higher RAM speeds needs to be tuned better to avoid this. For AMD this has mostly been done now (by capping some voltage at a certain level). For Intel not. However, no CPUs are dying with Intel, so they don't see a need there.

Also worth a watch:




Yes. If you don't plan on using XMP or EXPO, then there is no need to get a more expensive kit of DDR5-6000 or so. You might as well get a cheaper kit of DDR5-4800 without XMP/EXPO, because that's exactly what the pricier kit would run at, should you not enable EXPO.



Well, but that's a wrong assumption. All RAM will first boot at a safe JEDEC speed, these are the non-XMP/EXPO speeds of DDR5-4800, -5200, -5600. Most of the time you will see it boot at DDR5-4800 because that will be the basic profile that the RAM offers. This is done so that it can boot in all boards, with all CPUs. If it was set at DDR5-6000 right from the get-go, some configurations couldn't support it, so you couldn't even boot the system like that. Hence the extra step of enabling the profile.
Really appeciate your clarification here. It puts the whole AMD 'burning CPU's' into context.

Since i'm buying the 6000MT/s RAM i will then be using XMP for sure. Presumably the B650 Mortar will be fine running the RAM at this speed/temps.
 

citay

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Yes, DDR5-6000 shouldn't pose a big problem. Not for the board of course, the MAG B650M Mortar WIFI is a mostly passive component of the memory system, what speed you can hit more depends on the CPU (because it houses the IMC). And i don't necessarily mean the CPU model, more the IMC quality, which is sort of random. But that only becomes a big factor once you go into the mid-to-high-6000 range and above.

As for the RAM kit, i briefly mentioned, XMP is more for Intel, EXPO is more for AMD. The difference is, AMD sometimes has some peculiarities with the timings, which an EXPO kit takes into consideration, but an XMP kit might not, although in principle they are both universally compatible. So what i would suggest, make sure you actually get an EXPO variant of that Kingston Fury Beast DDR5-6000 (for example KF560C36BBEK2-64), because there are XMP-only variants of it too (the EXPO kits by Kingston are always EXPO+XMP). By getting such an EXPO kit for the AMD platform (and an XMP kit for an Intel platform respectively), you avoid any potential pitfalls there.
 

mortar_user_64GB

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Yes, DDR5-6000 shouldn't pose a big problem. Not for the board of course, the MAG B650M Mortar WIFI is a mostly passive component of the memory system, what speed you can hit more depends on the CPU (because it houses the IMC). And i don't necessarily mean the CPU model, more the IMC quality, which is sort of random. But that only becomes a big factor once you go into the mid-to-high-6000 range and above.

As for the RAM kit, i briefly mentioned, XMP is more for Intel, EXPO is more for AMD. The difference is, AMD sometimes has some peculiarities with the timings, which an EXPO kit takes into consideration, but an XMP kit might not, although in principle they are both universally compatible. So what i would suggest, make sure you actually get an EXPO variant of that Kingston Fury Beast DDR5-6000 (for example KF560C36BBEK2-64), because there are XMP-only variants of it too (the EXPO kits by Kingston are always EXPO+XMP). By getting such an EXPO kit for the AMD platform (and an XMP kit for an Intel platform respectively), you avoid any potential pitfalls there.
Ive been advised on here about a kit that suits my needs, whcih is indeed an EXPO kit by Kingston. However, after just checking the CPU page of the 7950x, it seems to indicate that the fastest ram that is compatible with it is far lower than 6000MT/s (5200MT/s), could this be correct?
 

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RemusM

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Ive been advised on here about a kit that suits my needs, whcih is indeed an EXPO kit by Kingston. However, after just checking the CPU page of the 7950x, it seems to indicate that the fastest ram that is compatible with it is far lower than 6000MT/s (5200MT/s), could this be correct?
Yes.
AMD guarantees only up to 5200MHz memory speed for all the current CPUs.
But that's true using the default voltages on both memory (1.1V for DDR5) and CPU IMC.
Raising the voltages on both sides will lead to higher memory speeds.
But that with also raise the temperatures and it's an open door to stability issues.
Higher the EXPO rated speed is, higher the risks are.
But you should be ok with your 2 x 32GB kit at 6000MHz.
 

citay

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Check the video i linked earlier. Both Intel and AMD always give very conservative numbers for their RAM speed support, in order not to have any responsibility for problems at higher speeds. By officially supporting only tame JEDEC speeds, it's up to the board makers to boast with what maximum speeds their boards can support (even though the CPU's IMC plays a major part in the memory system).
 

RemusM

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Both Intel and AMD always give very conservative numbers for their RAM speed support, in order not to have any responsibility for problems at higher speeds.
That's not true.
Those speeds are guaranteed for default voltages (1.1V for DDR5 and similar voltages for CPU IMC)
 

mortar_user_64GB

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Check the video i linked earlier. Both Intel and AMD always give very conservative numbers for their RAM speed support, in order not to have any responsibility for problems at higher speeds. By officially supporting only tame JEDEC speeds, it's up to the board makers to boast with what maximum speeds their boards can support (even though the CPU's IMC plays a major part in the memory system).
I started watching the De8auer video, it was interesting and from a comment he made I went to check the official AMD RAM Max speed - and so saw this about 5200 being the maxiumum - anything over and some some motherboard manufacturers say your warranty could be voided.

I suppose the question is whether the motherboard I have would be adequate. I was torn between the the Mortar and Tomahawk and am going for the Mortar..however, the Tomahawk has better/more - VRM's14 x80A VRM's, whereas the Mortar has 12 x 80A. When you talk about board makers and what speeds a model of their scan tolerate, will this have antying to do with the quality/power of the VRM's?(i.e should I get the Tomahawk if I want to be more sure the EXPO profile will work ok?)
 

mortar_user_64GB

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Yes.
AMD guarantees only up to 5200MHz memory speed for all the current CPUs.
But that's true using the default voltages on both memory (1.1V for DDR5) and CPU IMC.
Raising the voltages on both sides will lead to higher memory speeds.
But that with also raise the temperatures and it's an open door to stability issues.
Higher the EXPO rated speed is, higher the risks are.
But you should be ok with your 2 x 32GB kit at 6000MHz.
I guess 6000 isnt crazy fast - ive seen some 7200 ones. However, i guess the question is whether my mobo will be ok using the EXPO profle. Although it's B650 model (Mortar B650M), it had the best VRM's out the all the other B650M boards
 

RemusM

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I guess 6000 isnt crazy fast - ive seen some 7200 ones.
Not anymore.
With the current AMD CPUs anything faster than 6200 is not stable anymore (due to the latest VSOC limitation to 1.3V).
2 x 16GB at 6000MHz is doable for almost any 7XXX CPU.
But 2 x 32GB at 6000MHz might be a bit problematic (unstable).
Let's hope you'll be lucky here.
In case of stability issues you need to raise a bit the voltages or to set the memory speed to 5600MHz.
 

citay

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That's not true.
Both statements can be true. The CPU makers could just officially allow up to a certain higher CPU I/O supply voltage for DDR5 when used with XMP/EXPO profiles up to certain speeds. Then the whole debacle with the board raising some voltages too much could be prevented, because the board makers might adhere more to the official specs. Right now the CPU makers have the official limit (conservative), and the board makers just go crazy in their BIOS for XMP/EXPO, until some CPUs die and they are forced to lower it.

I started watching the De8auer video
Well, then keep watching, he later goes on that the "warranty voided" situation is quite ridiculous.


however, the Tomahawk has better/more - VRM's14 x80A VRM's, whereas the Mortar has 12 x 80A. When you talk about board makers and what speeds a model of their scan tolerate, will this have antying to do with the quality/power of the VRM's?(i.e should I get the Tomahawk if I want to be more sure the EXPO profile will work ok?)
Has nothing to do with the VRM. First off, 95% of that VRM is for VCore (CPU core voltage). The uncore/SoC part draws magnitudes less power, you usually only have one or two phases dedicated to that. And the RAM itself has its own VRM, directly to the right of the RAM slots (also just a one-phase, maximum two-phase).
 

mortar_user_64GB

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In case of stability issues you need to raise a bit the voltages or to set the memory speed to 5600MHz.
This was my next question - how to deal with it if there is instability. So, all i need to do is force/downclock the memory 5600MHz (or increase the volts - yikes 😬 ) and it should be fine
 

RemusM

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This was my next question - how to deal with it if there is instability. So, all i need to do is force/downclock the memory 5600MHz (or increase the volts - yikes 😬 ) and it should be fine
It depends on the voltages in your particular case (CPU + RAM + Mobo + PSU).
So even if you'll find someone with the "same" 4 components, the voltages won't be the same as yours!
In any case, the safest route in case of instability is to use the EXPO settings, but set the memory speed to 5600MHz.
 
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