Asus Crosshair VIII Dark Hero with 3600Mhz ram - unstable

[janskit22]

Hi ROG team, I've been running the motherboard above with 5950x and 64GB RAM (Corsair CMH32GX4M2Z3600C18, 32gb kit x 2, 3600mhz).

The system is unstable and in Prime95 I get immediately hardware rounding errors, OCCT throws hardware errors, too. This is with DOCP configured to 3600mhz.
The moment i drop it to 3400mhz, system is stable and hardware errors go away.
Where should i start looking next? different ram ? any settings i should look at?

[RedSector73]

If the memory is new, you should RMA it.

DDR4@3600 CL16 is ideal.

[janskit22]

i've had it for a few months, it's 3600cl18

[MeanMachine]

janskit22 wrote:
Hi ROG team, I've been running the motherboard above with 5950x and 64GB RAM (Corsair CMH32GX4M2Z3600C18, 32gb kit x 2, 3600mhz).

The system is unstable and in Prime95 I get immediately hardware rounding errors, OCCT throws hardware errors, too. This is with DOCP configured to 3600mhz.
The moment i drop it to 3400mhz, system is stable and hardware errors go away.
Where should i start looking next? different ram ? any settings i should look at?

Just to clarify: It seems your RAM consists of two kits at 32GB and if so this is a NO NO. Mixing kits like that is never a good idea and can/will cause issues. As it's explained well here and by RAM manufacturers, you should not combine kits but have a single matched kit that have been binned at the factory to prevent a mismatch.

The 5950X officially supports up to 3200Mhz so there would be no D.O.C.P profile for easy overclocking at 3600mHZ.
It will be the strength of the IMC that will determine if you will attain the rated frequency of your RAM and that there is no guarantee.

The only better RAM would be a kit with lower CL say CL14 at 3200Mhz
If you are able to Overclock to 3400Mhz and stable then leave it at that.

What reason do you have for 64GB?

[janskit22]

hi,

to be honest mixed kits did cross my mind, perhaps I should change to a single kit.

I will do some testing with one kit removed to see if that makes a difference.

My reason for 64gb? lots of memory hungry VMWare workstation virtual machines.

The 5950X officially supports up to 3200Mhz so there would be no D.O.C.P profile for easy overclocking at 3600mHZ.

Interesting - there certainly is the DOCP-3597Mhz profile in my bios!

[RedSector73]

hmm if it's a mixed kit, try SOC of 1.1v to 1.15v and see how it goes.
https://rog.asus.com/forum/showthread.php?122231-Problems-with-4-sticks-of-RAM-(64gb-3600)-stability...
Also make sure you kept the kits together, that is kit 1 in A2 & B2 and kit 2 in A1 & B1. (not sure - check the serial numbers to work out the kits again) You can also try swapiing the kits around if this still fails@ rated speed.

The kit in A2 & B2 is used to determine the sub timings. You could also run kits on there own and use ZEN Timings to extract any differences in the kits and then manually tune, if the bump in SOC voltage does not get the job done and provide stabilty@rated speed.
https://zentimings.protonrom.com/

MeanMachine wrote:
The only better RAM would be a kit with lower CL say CL14 at 3200Mhz
If you are able to Overclock to 3400Mhz and stable then leave it at that.

Is that lowest for 64gb kit @3200 CL14 ?

I run 32gb kit DDR4@3800 CL14 and pretty sure there is DDR4@3600 CL14 for 64gb kits
https://www.gskill.com/product/165/326/1578906135/F4-3600C14Q2-64GTZNB
https://www.gskill.com/product/165/326/1604306180/F4-3600C14Q-64GTZN

janskit22 wrote:
perhaps I should change to a single kit.

If you are changing, look at g.skill. NEO branding is for Ryzen.

[Hardstyle]

Hello,
Same problem as you,

I've switch 3600 corsair DDR with g skill ones and i dont get any crash.

[Silent_Scone]

Hello,

Please have a read of this information piece regarding mixing memory kits and why it's ill-advised. Whereas the post is now fairly old, the fundamentals of overclocking memory and the laws behind electrical signal integrity remain very much the same.

https://rog.asus.com/forum/showthread.php?57038-Don%92t-combine-memory-kits!-The-meat-and-potatoes-o...