[SOLVED] Xeon 8280 dual processors don't work together ?

[dmdang]

[Updated] I use this system to simulate on Ansys HFSS.
[Updated1] Problem solved. Please read post #14
Hi everyone,

I'm building a system using dual xeon platium 8280. Everything works well until I run my task. It seem that the two CPUs can not work in parallel, you can see in picture below, only 1 CPU works when I do my task.

I try to set number of processor in system configuration to 56 cores but when my computer restart, it only shows 1 CPU with 28 cores.


image image

Here is my main board

image image

Please help me. Thanks a lot.

 

[rgd1101]

what the os?

 

[USAFRet]

I try to set number of processor in system configuration to 56 cores but when my computer restart, it only shows 1 CPU with 28 cores.

Set this where?
Screencap please.

 

[dmdang]

Set this where?
Screencap please.

Here it is.

what the os?

I use windows 10 Pro.

 

[USAFRet]

Uncheck that box!

That puts ALL CPUs, ALL cores into play.

 

[dmdang]

Uncheck that box!

That puts ALL CPUs, ALL cores into play.

But they don't work together, bro. I can only choose to run on CPU1 or CPU2, but not both at same time.

Please see the picture below. I have 2 systems, one is dual xeon 8280 and remaining is dual xeon 2680. You can see in 2680 system, I don't need to choose which core is used.

 

[USAFRet]

But they don't work together, bro. I can only choose to run on CPU1 or CPU2, but not both at same time.

Dual CPU is also based on the application. The vast majority of applications are not dual CPU aware.

So what application, and are you 100% sure of its capabilities?

 

[dmdang]

Dual CPU is also based on the application. The vast majority of applications are not dual CPU aware.

So what application, and are you 100% sure of its capabilities?

I used the same application for my 2 systems. The problem only on system using dual xeon 8280.

 

[DSzymborski]

It's very difficult for anyone to give more than a very general answer for Mystery Application.

 

[dmdang]

It's very difficult for anyone to give more than a very general answer for Mystery Application.

Sorry bro. I use Ansys HFSS version 2021.

 

[USAFRet]

Sorry bro. I use Ansys HFSS version 2021.

Have you asked Ansys?
https://www.ansys.com/support

 

[dmdang]

Have you asked Ansys?
https://www.ansys.com/support

No, I have not. However, I tested with prime95 and other softwares, the same issue with them, only 1 of the CPUs can run at a time.

 

[USAFRet]

No, I have not. However, I tested with prime95 and other softwares, the same issue with them, only 1 CPUs can run at a time.

As said, the software needs to be multi-CPU aware.

Just because there are 2 does not mean the software can use 2.

Contact Ansys, to verify their particular software package is multiCPU aware.

 

[dmdang]

As said, the software needs to be multi-CPU aware.

Just because there are 2 does not mean the software can use 2.

Contact Ansys, to verify their particular software package is multiCPU aware.

Hi bro,

I found the problem, it comes from hyperthreading. Windows 10 Pro only allows 64 cores per processor group, hyperthreading doubles my physical core so I have 112 core in total. Therefore, 112 will be divided into 2 processor groups. I disabled hyperthreading and everything goes ok.
Hyperthreading can cause problem on Ansys's performance so disabing it is a good idea.

 

[rgd1101]

https://www.anandtech.com/show/15483/amd-threadripper-3990x-review/3
there a workstation pro that go up to 256.
MS windows chart show "cores" not threads ???

 

[dmdang]

https://www.anandtech.com/show/15483/amd-threadripper-3990x-review/3
there a workstation pro that go up to 256.
MS windows chart show "cores" not threads ???

Exactly bro, it's too confusing.