T7810 second cpu not recognised

Question

I have two identical single cpu T7810 workstations working fine individually. I have placed the the cpu and memory from one into the other (and vice versa to check) but neither seem recognise the second cpu at the bios level. Does something need enabling or is the second socket disabled?

Any help is appreciated.

mazzinia_ · Answer

Could you check the Revision level of the 2 cpus , using cpu-z ? ( portableapps.com ) To work together, the 2 cpus must have the same revision level, or at most one revision different

Sjblack83 · Answer

Will do, thank you.

Sjblack83 · Answer

Both CPU's are branded as (I popped the cover and removed the heat sinks) - SR20J (Intel Xeon E5-1650 v3) Is that enough to go on?

mazzinia_ · Answer

I 'think' yes ( using the sw was simpler, I think ). They have both the same stepping. Ok time to dig further. Do both 7810 have the same bios version ? some bios updates may include updating parts of the cpu microcode ( not just the bios itself ) if I'm not mistaken.

mazzinia_ · Answer

https://www.intel.com/content/www/us/en/support/articles/000055672/processors.html

https://www.intel.com/content/www/us/en/support/products/5982/processors/processor-utilities-and-programs/intel-processor-identification-utility.html

Please check each cpu revision. Those must be identical.

Sjblack83 · Answer

I'll check this as soon as i can

Sjblack83 · Answer

Not sure about that i did run a bios update after installing the cpu.

WizardOfBoz2 · Answer

Maybe check each CPU sequentially (singly) in the target chassis?  If they both work in that chassis them this is weird...

Sjblack83 · Answer

I have tried both cpu's in the primary socket and they both work fine.

Sjblack83 · Answer

The cpus are identical in every classification.

bradthetechnut · Answer

Here's something I don't know, so I get to learn here too. Is there anything in BIOS that can shut off the 2nd CPU? If there is, yet the 2nd CPU is checked off as being on, uncheck it, click Apply. Then recheck it and click Apply. If not, I'm thinking it might be the MB.

I say that because whenever I've added drives, I've had to do that to get Windows to see the added drives.

Sjblack83 · Answer

There is nothing in the bios relating to the cpu I have updated the bios with both chip in the primary socket. Still no luck, I have tried both chips in both chassis too, still nothing. All I can assume is the mobo is crippled by design as whats the likelihood of both being broken?

bradthetechnut · Answer

I was thinking about that and think you're right - MB is crippled by design.  It's hard to picture what on earth would do that otherwise tested in 2 units.

mazzinia_ · Answer

This is getting weird. Those systems were made to run up to 2 cpus, and without all this kind of mess. Now.... by chance one could be defected, yes... but both is a bit impossible unless purchased together, both motherboards are from the same production batch and the batch was all defected without nobody realizing ?

I "think" they do some quick burn in test upon assembling and pre-shipping to the buyer, but those are based on the configuration purchased.

mazzinia_ · Answer

I feel dumb .... I read the posts and this totally went in from one ear and out from the other, as they say.

Intel Xeon E5-1650 v3 << these are the 2 cpus installed now.

The e5-1650 is a cpu made for single sockets usage.

You need to use e5-2xxx v3 cpus ( made to be used as single, or as duals )

Precision Fixed Workstations

T7810 second cpu not recognised

Was this post helpful?