Mixing RAMs with the same specs

[ludecan]

Hey guys, a couple of years ago I bought this CMK32GX4M2B3200C16 2x16GB 16-18-18-36 1.35V memory kit.

Now I want to expand that on a new computer and I find this CMK64GX4M2E3200C16 2x32GB 16-18-18-36 1.35V memory kit.

Part numbers are not the exact same but the specs seem to be down to the voltages and latencies.

Question is will I be able to expand my 32GB to 96GB with the new kit like this? Are there any problems to be expected by mixing them?

Thanks in advance

[c-attack]

You should always expect to be required to manually set and tweak your timings when mixing kits. You can’t set XMP and be done. Additionally you are mixing different densities (32GB and 16) and that amplifies the difficulty. Not sure what motherboard you are using, but handling 2x32GB is going to be challenging enough for most boards. The odds are not really in your favor. 
 

Im not sure how much more utility you get from 96 vs 64GB, but there more obvious solution would be a straight swap. However you may want to make sure your mb/cpu combination can handle 32GB modules first. 

[ludecan]

Hey, thanks for the reply, wasn't sure about being able to mix and match. Bummer that XMP won't work.

Mobo is an ASUS TUF GAMING Z690-PLUS WIFI D4, it should support up to 128GB. CPU is an I7 12700KF which also should.

Just double checked and both memory kits are supported by the motherboard, so that should be one less obstacle.

Long story short, it's likely to require some tweaking for it to work properly right?

 

[c-attack]

At a minimum it will require you to manually set 3200 MHz, 16-18-36 on the primaries, and then a specific VCCIO and SA voltage. It’s those last two IO and SA voltages that are likely to need tweaking. Even between different examples of the same cpu you will see different requirements. I don’t know how it will respond to mixed densities on the 16GB and 32GB modules.  That is likely to be the largest obstacle and having both kits on/off the QVL may not help with that. 

[ludecan]

Hey! So I went through with this and got the 64GB kit. Indeed it didn't work out of the box, when I plugged the new sticks and left them on XMP, Windows would crash very few seconds after booting with BSODs referencing memory errors.

So I went into bios and manually set the RAMs to 3200 MHz, 16-18-18-36 latencies and RAM voltage to 1.35v, but didn't find where to set the VCCIO and SA voltages. Still got crashes.

Then I noticed the XMP profile name said 18-20-20-36. So I set latencies to that and now it's working stable, ran prime95 memory stress test for ~15 minutes no problem.

I still prefer the extra size vs the lower latencies so this is better than nothing but it'd be better if they could run full speed.

Do you know if VCCIO or SA voltages go by other names? Or where could I find them in bios?

 

[c-attack]

For Asus, it should be almost to the bottom of the “AI tweaker” or Extreme Tuner (name varies by model). This is the column with all the major settings (Vcore, RAM frequency, other voltages), usually the second one from the left.  It should be listed as VCCIO and SA, but sometimes they write out ‘System Agent’ voltage. 

[ludecan]

Hey, so, followup on this topic, turns out I had a pretty outdated bios version, was on v0503 released on 2021 and now updated to 1404 from apr 2022.

Armoury Crate told me that I was on the latest bios version but clearly that wasn't the case.

After the update applying the XMP profile worked just fine with no need to tweak, so I'm running the RAMs at full speed like they should now.

Now I'd like to undervolt the CPU but that's another topic. Thanks for the help @c-attack