Not stable - DDR5 Corsair Dominator Titanium 96GB 2x (2x24GB) CMP48GX5M2X7200C36

[renanlofiego]

Hey guys! I'm new to ASUS ROG but I've always used Asus, I upgraded from my old i9 9900K to an i9 14900KF with Asus ROG Maximus Z790 Dark Hero with 96GB on total with 2 DDR5 kits (2x24GB) CMP48GX5M2X7200C36 from Corsair Dominator Titanium and I can't stabilize it at 7200 Mhz, nor with XMP I and XMP 2.

As soon as I assembled the machine, the PC actually started to work fine, but soon after I noticed some errors, lags, etc., but then I couldn't even boot it anymore, I would like help with overclocking the memory to try to stabilize it, I only did some tests with 1 kit. at 7200Mhz and it worked perfectly running the BIOS memtest.

But when I assemble the 2 kits together that's where the problems start, today it runs at 6400 Mhz with XMP I active.

I didn't put anything here as an attachment because I'm going to wait for some help on what to send, etc., I have a little knowledge about overclocking because I did it on my i9 9900K during the 5 years I've been using it, but I'm still new to memory.

[warner_mark]

Running 96GB of DDR5 at 7200MHz is definitely pushing the limits! It's possible your CPU memory controller might not be quite happy at those speeds with both kits installed.

Try lowering the clock speed a bit, maybe to 6800MHz, and see if that helps with stability. You could also try adjusting the voltage slightly (+0.05v) to give the memory a bit more headroom.

[renanlofiego]

Well, I'm almost convinced that this is the problem and that I made the wrong choice, I should have gotten 2x48GB 6400 Mhz and overclocked it as far as possible...

I'm considering using 48GB at 7400Mhz or more if it's stable, I'll do some tests today, yesterday I tested at 7400 Mhz with just 2x24GB and it held up well.

[kashmala]

Welcome to the ASUS ROG community! It sounds like you're running into some common challenges when trying to stabilize high-speed DDR5 memory with multiple kits. Mixing two memory kits, even if they're the same model, can often lead to stability issues because they aren't factory-tested together, especially at higher frequencies like 7200 MHz.

Here are a few steps you can try to stabilize your system:

1. Manual Tuning: Instead of relying solely on XMP profiles, try manually adjusting the memory settings. You can start by slightly increasing the DRAM voltage (VDD and VDDQ) and tweaking the memory controller voltage (VCCSA or VDDQ_TX). Sometimes, loosening the primary timings a bit can also help with stability.

2. Lower the Frequency: If stability issues persist at 7200 MHz, try lowering the frequency incrementally. You mentioned it runs at 6400 MHz with XMP I active, so you could start from there and slowly increase the frequency while testing stability.

3. Test with One Kit First: Since you mentioned that one kit works fine at 7200 MHz, test each kit individually to ensure they can both run stable at that speed. This will help you identify if one kit is less capable or if the issue only arises when both kits are used together.

4. Adjust System Agent Voltage (VCCSA): Increasing the VCCSA slightly can sometimes help with memory stability when using high-speed DDR5.

5. BIOS Update: Ensure your BIOS is up to date, as newer BIOS versions often include memory compatibility and stability improvements.

6. Test Stability: Use tools like MemTest86, Prime95, or other memory stress tests to check for stability after each adjustment.

   If you’re still having trouble, you can share your current settings, and the community can offer more targeted advice. Include details like the current DRAM voltage, timings, and any adjustments you've already made. This will help us give you the most accurate guidance. 

    

    4o

[renanlofiego]

 Thank you, I'll send it, but I'm seeing that people say that 2 kits together don't match. 😔

[madao1945]

As many experts have already mentioned, using four DDR5 memory cards will cause problems. It seems that the correct usage is to use two cards.

[renanlofiego]

That's right, I've seen people commenting on this...

Maybe in the future I'll consider changing the modules to 96Gb (2x 48GB). Thank you 

[Silent_Scone]

Hi @renanlofiego 

Don't combine memory kits. Memory kits are binned by the memory vendor in the density in which they aresold. If you increase the desnity by adding more DIMMs , regardless if they're the same part number/memory kit, the timings, voltage are no longer valid. 

You can find more information on the topic here.

[renanlofiego]

I understand

You commented on the voltages being different, and if I find the voltages of each memory module, would it work?

I've been doing some tests here, it seems stable at 6.400 Mhz and to be honest, for my use here I'm not seeing a difference at the moment.

But I'll take a look at this post that indicated. Thank you. 

[Silent_Scone]

Not just voltage. The voltage, timings *and* frequency. Memory vendors do not make concessions for users pairing two kits together. The kit simply isn't binned in this way. Plus as others have mentioned already, 7200MT with 4 DIMMs isn't possible this gen.