HP Z640 Memory Error after CPU upgrade

[PC_Builder]

I recently purchased a HP Z640 with an e5-2620v3. I loaded up the 4 RAM slots with 128GB (4x32gb of 2400mhz), updated the bios to the latest version available, 0.2.59 A, and loaded Windows 10 x64. All was well.

I just purchased a E5-2697v4 cpu and installed it into the z640. It failed to boot and gave 5 beeps and red LED flashes. That should indicate a memory error. I removed a pair of Dimms from slots and it boots normally. I have a LOT of identical 32GB Dimms so I attempted to isolate a bad one but was unsuccessful. If I switch back to the 2620v3, the memory error goes away, all ram is recognized and it boots normally. I also tried a pair of 16GB Dimms and they cause the same error when installed with this CPU. I am following the slot population order dictated by HP.

I have a second 2697v4 and was going to purchase a CPU riser but don't want to do that until I know why the ram issue is occurring. 

Any advice?

[NonSequitur777]

@PC_Builder,

Welcome to our HP User Forum!

I certainly see no compatibility issues with your Xeon E5-2697 v4 processor: https://cpu-benchmark.org/compare/intel-xeon-e5-2697-v4/intel-xeon-e5-2620-v3/, and, as they would say, it should work just fine.

This may very well be something you already tried, but under "Diagnostics & Support Tools" there is a "Fast Test" (4 minutes) and an "Extensive Test" (+2 hours) as found here: HP Z640 Workstation Troubleshooting | HP® Customer Support.

Speaking of Xeon processor upgrading, you may find this User observation helpful: E5-46xx v4 processors work in the Z440, Z640 and Z840 workst... - HP Support Community - 8234687.

Kind Regards,

NonSequitur777

[PC_Builder]

Thank you for the reply. 

I did run the tests with no issues found. 

Further investigation seems to point to memory slot 4 specifically as the issue. It works fine with the previous processor and causes a failure to boot with the 2697v4. 

All I can think is that there is a bit of contamination in the socket from when I swapped cpu. It seems odd that it only affects a single slot. I will check that and retry. 

*** UPDATE ***

I removed the CPU and blew out the socket with compressed air. Nothing much came out. Pins all look ok. Reinstalled the CPU and checked again. Slot 4 still causes the 5 beeps. 

The ram is all identical: Hynix 32gb 2Rx4 PC4-2400T-R81-11, HMA84GR7MFR4N-UH. Pulled from the same server that had the 2697v4 chips.

[DGroves]

keep in mind that on newer systems (like this one) the memory controller resides in the CPU itself

your error may be due to a damaged/failing CPU or a engineering sample (pre retail/OEM release ) CPU

since replacing the new cpu with the original cpu resolves the problem, we can rule out bent pins in the cpu socket

[PC_Builder]

Thank you. This is a puzzle then. The cpu was taken from a working but retired blade server. That server was dual-CPU and had 768gb of 32gb ram sticks. It had ram in all 4 banks. I am using the same ram from that system. 

CPU is:

E5-2697v4 

SR2JV 2.3GHZ

I can try the 2nd 2997v4 and see if it has the same behavior. 

[DGroves]

your ram is not on the HP approved list, try using a single (or two)  approved ram module(s)