Dual CPU HP Z8 G4 - Going to sleep causes CPU1 to lose all memory modules

[Reprobate]

Hello, first post here but been a member quite a while, coming to ask for help with a confusing issue...

I have a Dual CPU HP Z8 G4 that when the unit goes to sleep it does not come back on. Clicking the mouse does re-wake but leads to a blank screen and eventually all the fans come on maximum.

When I turn it off and on again with power cable connected I get a BIOS warning that the memory has changed. All of the memory modules for the second CPU are completely gone in both the BIOS and Windows. CPU0 modules remain and are seen by windows. There are 6 DIMMs per CPU.

This seems to be able to be fixed by disconnecting the power totally and then reconnecting, I get a warning that the memory has now doubled again.

I tried swapping the memory modules, and even swapped out the CPUs but I still have the exact same issue, which makes me worry about the motherboard. The machine appears to work fine if this action is not triggered.

Has anyone heard of this strange behaviour? Is it anything that I need to be worried about with hardware failure etc?

Thanks for any advice.

 

[RolloZ170]

what RAM are you using ?
have you read the notes about S3 inthe manual ???
2. Sleep (S3 state) support:
- Sleep (S3 state) may not be supported with non-HP validated and qualified 64 GB LR DIMMs.
- Sleep (S3 state) is not supported with 128 GB 3DS LR DIMMs

 

[Reprobate]

I am using 8GB DIMMs, the factory installed ones, but thank you as this does make some sense. If the machine has touble with sleep states, I am thinking it's less likely to be hardware failing on me.