Question Motherboard or RAM Limitation?

[SyCoREAPER]

I'm new to the AMD world of desktops and am getting quite frustrated with RAM and motherboards. It's not like Intel where you turn on XMP and boom it works. I've been reading for 4 hours and am just caving and asking here.

RAM: Two identical Kits of VENGEANCE RGB 32GB (2x16GB) DDR5 DRAM 6400MT/s CL32 Memory
CPU: AMD 7800x3D
MB: Asus TUF x670e-plus

Per the MB manual it only supports 32GB? I can get 64GB to boot but no Expo. Not Expo I or II. Despite the RAM having XMP and the board supporting XMP it's not there.

I tried dropping the clock down while keeping it at 1.4v, Enabled the Context whatever it is called in both places and it gets a little further but it still black screens at 6000Mhz. Not going any lower.

32GB and Expo works fine and is stable.

A few people suggested doing 2x32GB instead of 4x16GB because achieving CL32 let alone CL36 will be unlikely with 4 DIMMs?

Is that worth trying 2x32GB or is 32GB likely the best I can hope to achieve at frequency and low clock? Should I get a different board? I have to choose from 1 of the 3. The trip to Microcenter is a long fricken trip that I don't want to have to make again.

Before anyone asks why I need 64GB, because developers are getting lazy and sloppy and have seen a few games where the recommended is 32GB, it's only a matter of time before the minimum becomes 32GB.

 

[Lutfij]

Asus dubs their ram overclocking option as D.O.C.P instead on the AMD platform.

A few people suggested doing 2x32GB instead of 4x16GB because achieving CL32 let alone CL36 will be unlikely with 4 DIMMs?
This is because even on Intel's 12th Gen platform, you couldn't get 4 DIMMS to work with high frequencies, at first launch. It was after a couple of BIOS revisions as well as ram kits that the option to populate all 4 slots with high capacity, high frequency ram sticks became available to the masses. The Integrated Memory Controller didn't like the stress and often resulted in a no-POST scenario.

RAM: Two identical Kits of VENGEANCE RGB 32GB (2x16GB) DDR5 DRAM 6400MT/s CL32 Memory
Got a link to the ram kit? For the sake of relevance, can you check and see what the PCB revisions on the ram kits are and if they're identical?

MB: Asus TUF x670e-plus
What BIOS version are you on for your motherboard?

 

[BFG-9000]

You cannot expect that much memory to just run at such high speeds, and are doing well to have random unmatched sets of sticks running at the default DDR5-5200. Each set may be rated to run at 6400 but not both together or they would've sold them as a 4x16GB set.

If you want faster, well there are only two sets of 4x16GB on that board's QVL above 6000, and they are Corsair CMT64GX5M4B6600C32 Ver 5.43.01 and CMP64GX5M4B6400C32W Ver 5.43.01.

There are 4 sets of 2x32GB on that list too: Corsair CMH64GX5M2B6600C32 Ver 5.43.01 and CMT64GX5M2B6400C32 Ver 5.43.01, plus Kingston KF564C32RSK2-64 and KF564C32RWK2-64.

Why reinvent the wheel and go overclocking off into uncharted territory, when the motherboard manufacturer has tested many sets and found some that work?

 

[SyCoREAPER]

Asus dubs their ram overclocking option as D.O.C.P instead on the AMD platform.

A few people suggested doing 2x32GB instead of 4x16GB because achieving CL32 let alone CL36 will be unlikely with 4 DIMMs?
This is because even on Intel's 12th Gen platform, you couldn't get 4 DIMMS to work with high frequencies, at first launch. It was after a couple of BIOS revisions as well as ram kits that the option to populate all 4 slots with high capacity, high frequency ram sticks became available to the masses. The Integrated Memory Controller didn't like the stress and often resulted in a no-POST scenario.

RAM: Two identical Kits of VENGEANCE RGB 32GB (2x16GB) DDR5 DRAM 6400MT/s CL32 Memory
Got a link to the ram kit? For the sake of relevance, can you check and see what the PCB revisions on the ram kits are and if they're identical?

MB: Asus TUF x670e-plus
What BIOS version are you on for your motherboard?

DOCP:
What I'm reading you're not wrong but is DOCP so that XMP works on AMD disguising as EXPO or is it its own thing or what am I reading? My board is showing EXPO 1, EXPO 2 and EXPO Tweaked (DOCP?).

Intel:
On my Intel rig I have 4x 16GB 4000Mhz (can't recall the CL) it's works with the exception that I can't see the BIOS or rather can't see anything until the MB logo and if I smash keys I still can't see the BIOS, so I'm at some strange in-between state but that's not relevant for my Question so I'll stop rambling on that.
To circle back though, I was referring to posts about this board supposedly supporting 64GB so long as it's 2x32GB but nobody ever comments back after someone suggest it worked for them.

RAM Link:
I was never able to find a datasheet but I also didn't look super hard. Newegg and Microcenter being the two bigger players selling it have the same model. Maybe an outlet exclusive model?
Corsair - CMH32GX5M2B640Z - v5.43.01


MB Firmware:
Version 3067 - 2024/12/16
I considered downgrading but also recall a BIOS update to tame voltage runaway for AMD using the burn-up time frame.

 

[BFG-9000]

From the QVL, ASUS has even certified that board for 192GB of memory, but only at 5200 CL38

Looks like the 4x16GB configurations above at 6400 and 6600 are only for 9000 series CPUs, but the four 2x32GB ones work on 7000 series too.

 

[SyCoREAPER]

You cannot expect that much memory to just run at such high speeds, and are doing well to have random unmatched sets of sticks running at the default DDR5-5200. Each set may be rated to run at 6400 but not both together or they would've sold them as a 4x16GB set.

If you want faster, well there are only two sets of 4x16GB on that board's QVL above 6000, and they are Corsair CMT64GX5M4B6600C32 Ver 5.43.01 and CMP64GX5M4B6400C32W Ver 5.43.01.

There are 4 sets of 2x32GB on that list too: Corsair CMH64GX5M2B6600C32 Ver 5.43.01 and CMT64GX5M2B6400C32 Ver 5.43.01, plus Kingston KF564C32RSK2-64 and KF564C32RWK2-64.

Why reinvent the wheel and go overclocking off into uncharted territory, when the motherboard manufacturer has tested many sets and found some that work?

Not sure where you're going with that. If you mean matched as in one package/SKU for 4 sticks in one physical package, then I've not come across them in person and only by PC parts in store anymore because I'm tired of getting people's Amazon returns packages as new (despite Shipped and Sold by Amazon New).
Otherwise they are 100% identical models and version numbers which hardly makes them random. Also they aren't JEDEC 5200, they are JEDEC 4800, so slow as a turtle without an overclock. Unless AMD is astronomically picky, I've never had an issue with Intel mixing different batches so long as they were the exact same sticks and revisions.
Those lists are rarely maintained and many kits either no longer exist or are cost prohibitive, not referring to your post.

 

[SyCoREAPER]

From the QVL, ASUS has even certified that board for 192GB of memory, but only at 5200 CL38

Looks like the 4x16GB configurations above at 6400 and 6600 are only for 9000 series CPUs, but the four 2x32GB ones work on 7000 series too.

That just goes to show how inconsistent Asus is but they also have decent build quality on the AMD side. If it's been tested that high, they put 32GB in the manual? Sure the manual could be outdated but the lack of updating speaks volumes.

 

[BFG-9000]

Well they keep updating that list as long as they are still producing the board + testing it, and may eventually update the manual too. Sure finding specific RAM costs more, but a nice thing about having a recent board is at least you can still get the ones listed on the QVL at all--that is most definitely not the case years later when most people are looking for a RAM upgrade on their old system. By then you may have no choice but to buy and test out many sets.

If it's on the QVL then you are only overclocking the CPU's memory controller since the motherboard and RAM are certified by their manufacturers to run at those speeds. Mixing sets means not even the memory manufacturer has tested that configuration... so you are the pioneer going where none have gone before, and get to test for if it works or not. At least it should be no surprise if automatic overclocking options like XMP don't work.

AMD has historically been more picky with memory, at least at first until many AGESA updates down the road. But at a couple years old, Zen 4 should be pretty mature by now.

 

[SyCoREAPER]

Well they keep updating that list as long as they are still producing the board + testing it, and may eventually update the manual too. Sure finding specific RAM costs more, but a nice thing about having a recent board is at least you can still get the ones listed on the QVL at all--that is most definitely not the case years later when most people are looking for a RAM upgrade on their old system. By then you may have no choice but to buy and test out many sets.

If it's on the QVL then you are only overclocking the CPU's memory controller since the motherboard and RAM are certified by their manufacturers to run at those speeds. Mixing sets means not even the memory manufacturer has tested that configuration... so you are the pioneer going where none have gone before, and get to test for if it works or not. At least it should be no surprise if automatic overclocking options like XMP don't work.

AMD has historically been more picky with memory, at least at first until many AGESA updates down the road. But at a couple years old, Zen 4 should be pretty mature by now.

That's a fair assessment but and I know this sounds like I'm crapping on AMD, there just aren't many options. Ar their price points, they are either older or very unimpressive/low spec boards. Being that a older lower-mid board still costs as much as it does, in not willing to dump a ton of money on a more expensive board that offers what will should have been there in the first place.

The fact that the memory situation is this bad has me wondering outside of the x3d chips performance what the AMD hype is all about. I only even went AMD because I got the processor for free when I bought the reference 7900xt.

I guess tomorrow I'll try for the 2x32GB and see how it goes. Turns out I'll be headed past Microcenter this week multiple times regardless. Worst case I stick with 32GB for now. So I'll guinea pig it.

Side note, what happened to the DDR5 trend where they were doing goofy sizes like 48GB, 96 GB, etc?

 

[CountMike]

That's a fair assessment but and I know this sounds like I'm crapping on AMD, there just aren't many options. Ar their price points, they are either older or very unimpressive/low spec boards. Being that a older lower-mid board still costs as much as it does, in not willing to dump a ton of money on a more expensive board that offers what will should have been there in the first place.

The fact that the memory situation is this bad has me wondering outside of the x3d chips performance what the AMD hype is all about. I only even went AMD because I got the processor for free when I bought the reference 7900xt.

I guess tomorrow I'll try for the 2x32GB and see how it goes. Turns out I'll be headed past Microcenter this week multiple times regardless. Worst case I stick with 32GB for now. So I'll guinea pig it.

Side note, what happened to the DDR5 trend where they were doing goofy sizes like 48GB, 96 GB, etc?

Maximum RAM with consumer grade 64bit CPUs is 128GB so above 32GB per module is not practical.