[SOLVED] Corsair Vengeance RAM Speed incorrectly detected?

[HarDHar]

Hey, I'm running 4 sticks of Corsair Vengeance DDR4-3600 RAM and the BIOS on my ASRock B550M Steel Legend MB is detecting them as being maxed out at 2132 Mhz. CPU-Z also shows this same max bandwidth, but even the part number that is listed on CPU-Z has a 3600 in it. I'm not sure if there's something I have to do with the XMP or what. I do have the newest version of the BIOS, 1.52, if that's important. I can also provide more information if needed, so just ask. Thanks!

 

[Darkbreeze]

There is ALWAYS "something you have to do with the XMP". It is never just automatically configured by default for high speed memory kits unless the XMP profile speed is the same as the natively supported maximum speed and even then it's STILL highly recommended that you set the XMP profile in the BIOS because natively it may not settle on the most optimal timings as those that are hard coded into the memory module by the manufacturer.

Go into the BIOS, and set/enable the XMP profile.

The other question is whether the kit is even compatible with your motherboard AND whether it will run with four DIMMs at 3600mhz. If the memory kit is not on the motherboard QVL list OR does not show as validated on the Corsair memory finder utility, then you might have a tough time getting it to run at it's advertised speed. All you can do is try.

In the meantime, it would be helpful to know the EXACT model of the memory kit AND whether or not you purchased one kit with four DIMMs in it, or two separate kits with two DIMMs in each one?

 

[HarDHar]

There is ALWAYS "something you have to do with the XMP". It is never just automatically configured by default for high speed memory kits unless the XMP profile speed is the same as the natively supported maximum speed and even then it's STILL highly recommended that you set the XMP profile in the BIOS because natively it may not settle on the most optimal timings as those that are hard coded into the memory module by the manufacturer.

Go into the BIOS, and set/enable the XMP profile.

The other question is whether the kit is even compatible with your motherboard AND whether it will run with four DIMMs at 3600mhz. If the memory kit is not on the motherboard QVL list OR does not show as validated on the Corsair memory finder utility, then you might have a tough time getting it to run at it's advertised speed. All you can do is try.

In the meantime, it would be helpful to know the EXACT model of the memory kit AND whether or not you purchased one kit with four DIMMs in it, or two separate kits with two DIMMs in each one?

Sorry, I should have clarified. The XMP profile is enabled at 3600, but it is still detecting the sticks as being maxed out at 2134. I can't find the memory finder utility that you are talking about, but if you can direct me to it I would be happy to take a look at the memory with it. I'm also unsure where to find a qvl list for my motherboard, but I will keep searching.

The memory sticks were purchased in two 2x8 bundles, and the exact model is CORSAIR Vengeance RGB Pro 16GB (2 x 8GB) DDR4 3600 Model CMW16GX4M2D3600C18W (here is the link to the Newegg page if that helps). Thanks again for your assistance.

 

[HarDHar]

Sorry, I should have clarified. The XMP profile is enabled at 3600, but it is still detecting the sticks as being maxed out at 2134. I can't find the memory finder utility that you are talking about, but if you can direct me to it I would be happy to take a look at the memory with it. I'm also unsure where to find a qvl list for my motherboard, but I will keep searching.

The memory sticks were purchased in two 2x8 bundles, and the exact model is CORSAIR Vengeance RGB Pro 16GB (2 x 8GB) DDR4 3600 Model CMW16GX4M2D3600C18W (here is the link to the Newegg page if that helps). Thanks again for your assistance.

Updating, the ASRock website does not have an updated QVL list for my CPU, which is the Ryzen 5 5600x. However, on the generation below, my memory model is not listed.

 

[Darkbreeze]

Ok, so unfortunately you're probably going to have to wing it when it comes to memory compatibility based on the relative newness of your CPU model. It is unlikely that ANY of the motherboard or memory manufacturers have completed, or possibly even conducted compatibility testing on existing board models using the newer architecture. Probably they won't even bother to do that until there's been time to iron out some BIOS updates. That's usually the case.

In fact, Corsair isn't even showing ANY listings for ASRock X570 or B550 boards right now, which means they are probably in the process of retesting them, because they WERE listed before.

Despite any of that though, it probably doesn't even matter because it would not apply to your use of two separately purchased memory kits together. Up front, this is the most probable reason for your issue other than the fact that Ryzen has typically had specific speed limits that are reduced when using four DIMMs versus two on many motherboard chipsets. While this is for Matisse, it could be a contributing factor. Most systems won't run at higher than 3200mhz with four DIMMs on any of the Ryzen chipsets.

But while that IS a consideration, and I'd personally recommend Ryzen users stick to two DIMM kits even though there have been some early reports of improved memory performance with four DIMM single rank or two DIMM dual rank configurations, until such time as it is shown to be a viable configuration for all Zen 3 users. This, is probably the much more relevant issue:

https://forums.tomshardware.com/threads/amd-ram-compatibility.3210050/#post-19785792

 

[HarDHar]

Ok, so unfortunately you're probably going to have to wing it when it comes to memory compatibility based on the relative newness of your CPU model. It is unlikely that ANY of the motherboard or memory manufacturers have completed, or possibly even conducted compatibility testing on existing board models using the newer architecture. Probably they won't even bother to do that until there's been time to iron out some BIOS updates. That's usually the case.

In fact, Corsair isn't even showing ANY listings for ASRock X570 or B550 boards right now, which means they are probably in the process of retesting them, because they WERE listed before.

Despite any of that though, it probably doesn't even matter because it would not apply to your use of two separately purchased memory kits together. Up front, this is the most probable reason for your issue other than the fact that Ryzen has typically had specific speed limits that are reduced when using four DIMMs versus two on many motherboard chipsets. While this is for Matisse, it could be a contributing factor. Most systems won't run at higher than 3200mhz with four DIMMs on any of the Ryzen chipsets.

But while that IS a consideration, and I'd personally recommend Ryzen users stick to two DIMM kits even though there have been some early reports of improved memory performance with four DIMM single rank or two DIMM dual rank configurations, until such time as it is shown to be a viable configuration for all Zen 3 users. This, is probably the much more relevant issue:

https://forums.tomshardware.com/threads/amd-ram-compatibility.3210050/#post-19785792

So moving forward, if I am understanding correctly, it seems like I have 3 options: a) run it with two sticks, return the other two, and I should be able to hit 3600
b) run it with 4 sticks, but configure it to stay at 3200
or c) would it be better to send back the two kits I bought and buy a 4 piece? maybe one that is advertised at 3200 since that’s the fastest speed I can get anyway.
Maybe I’m also misunderstanding what my options are here, so I’m wondering what you would do if you encountered this problem. Thanks for all of your help so far!

 

[Darkbreeze]

I'd definitely return the second kit if you bought it recently and are able to do so, or both kits if they are both still returnable. Optimally anyhow, you would (Without some newer information changing this recommendation, which might come, and might mean that some very small gain that may not even be noticeable to 99.999% of people, to suggest a four DIMM difference exists officially) want to run the desired capacity using only TWO DIMMs if you want to run them at 3600mhz.

Let me say this though. Those 3600mhz CL18 DIMMs are moderately slower than a 3200mhz CL14 kit would be. Measurably.

A 3600mhz CL18 kit would have a true latency of 10nS.

A 3200mhz CL14 kit would have a true latency of 8.75nS.

The lower the true latency, the faster the memory performance will be, in general, all other things being equal.

So a pair of 3200mhz CL14 sticks might be a better option, and then simply return your other kit, and sell or keep the first kit, and just get the 3200mhz kit in the capacity you need.

But certainly there are probably steps to be taken before then to determine if all that is really necessary or not. The first thing I'd do is try each kit, separately, in the A2 and B2 slots, to see if they will run at the A-XMP profile specs without the other kit installed.

 

[HarDHar]

I'd definitely return the second kit if you bought it recently and are able to do so, or both kits if they are both still returnable. Optimally anyhow, you would (Without some newer information changing this recommendation, which might come, and might mean that some very small gain that may not even be noticeable to 99.999% of people, to suggest a four DIMM difference exists officially) want to run the desired capacity using only TWO DIMMs if you want to run them at 3600mhz.

Let me say this though. Those 3600mhz CL18 DIMMs are moderately slower than a 3200mhz CL14 kit would be. Measurably.

A 3600mhz CL18 kit would have a true latency of 10nS.

A 3200mhz CL14 kit would have a true latency of 8.75nS.

The lower the true latency, the faster the memory performance will be, in general, all other things being equal.

So a pair of 3200mhz CL14 sticks might be a better option, and then simply return your other kit, and sell or keep the first kit, and just get the 3200mhz kit in the capacity you need.

But certainly there are probably steps to be taken before then to determine if all that is really necessary or not. The first thing I'd do is try each kit, separately, in the A2 and B2 slots, to see if they will run at the A-XMP profile specs without the other kit installed.

Okay, after testing, both kits are able to run the 3600 XMP profile when put in the AS and B2 slots. It also works if both kits are installed, but the speed is manually set to 3200. Evidently I needed to do way more research before I bought memory for my new build Anyways, it seems like my best option is to return these two kits, and get a 2 stick kit that's 3200 but with CL14? In order to get the best performance out of my memory with the rest of my setup, that is.

 

[Darkbreeze]

Either way you want a 2 stick kit and you'll get about the same performance with a 3200mhz CL14 kit as you will with a 3600mhz CL16 kit, so either of them is viable and maybe choose based on price and the quality of the kit.

Personally I think you are better served looking at G.Skill Trident Z or Ripjaws kits. They tend to so far have better overall compatibility with Ryzen platforms in my experience, although any kit will certainly work if it has been validated as compatible.

Corsair has I think traditionally oriented their kits a little more towards Intel platforms when it comes to timings and such, but that has been changing for a while so it really just depends on the kit model.

I personally use G.Skill pretty much exclusively for my own builds.

Do you really NEED 32GB? Because it's much harder to get fast low latency 32 GB kits than it is for 16GB, but if you actually NEED more than 16GB then the difference in performance from HAVING more than 16GB will definitely outweigh any specific speed considerations or characteristics. If not, then sticking with 16GB might save you a lot of money.

 

[HarDHar]

Either way you want a 2 stick kit and you'll get about the same performance with a 3200mhz CL14 kit as you will with a 3600mhz CL16 kit, so either of them is viable and maybe choose based on price and the quality of the kit.

Personally I think you are better served looking at G.Skill Trident Z or Ripjaws kits. They tend to so far have better overall compatibility with Ryzen platforms in my experience, although any kit will certainly work if it has been validated as compatible.

Corsair has I think traditionally oriented their kits a little more towards Intel platforms when it comes to timings and such, but that has been changing for a while so it really just depends on the kit model.

I personally use G.Skill pretty much exclusively for my own builds.

Do you really NEED 32GB? Because it's much harder to get fast low latency 32 GB kits than it is for 16GB, but if you actually NEED more than 16GB then the difference in performance from HAVING more than 16GB will definitely outweigh any specific speed considerations or characteristics. If not, then sticking with 16GB might save you a lot of money.

Okay, perfect! I'll take that into consideration when I decide on a new purchase! Thank you so much for all of your help on this.

 

[Darkbreeze]

Anytime man.