[Anna Tian]

Hi,

I have a 4 CPUs workstation. I installed win7 system to it. But I found that win7 can only read 2 CPUs. That seems to be win7's uplimit. I'm gonna to run Fluent by that workstation. Could anyone give any suggestions on how to make the system run more CPUs? Shall I go for win server 2008 r2 or linux system for it?

[mnabi]

Originally Posted by Anna Tian

Hi,

I have a 4 CPUs workstation. I installed win7 system to it. But I found that win7 can only read 2 CPUs. That seems to be win7's uplimit. I'm gonna to run Fluent by that workstation. Could anyone give any suggestions on how to make the system run more CPUs? Shall I go for win server 2008 r2 or linux system for it?

Check in the Bios either the hyper-threading is set to ON

[Anna Tian]

Originally Posted by mnabi

Check in the Bios either the hyper-threading is set to ON

I think it is on. Because I also installed several hardware checking software, e.g. CPU-z. They all show that I have only 2 CPUs. And since i never changed the bios, I think it shall be on. Have you made win7 working with a 4 CPUs workstation? Any experience on that?

[JBeilke]

http://social.technet.microsoft.com/...7itprohardware

[mnabi]

Originally Posted by Anna Tian

I think it is on. Because I also installed several hardware checking software, e.g. CPU-z. They all show that I have only 2 CPUs. And since i never changed the bios, I think it shall be on. Have you made win7 working with a 4 CPUs workstation? Any experience on that?

Yes,we have win7 on Intel 4 cores, 8 cores, 16 cores, 32 cores, and also AMD 4 cores, 6 cores, and 32 cores. I never had such problem with win7. on all these PC's win7 functioned perfectly.

[flotus1]

mnabi how many CPUs (not the number of cores) are you talking about? And which specific version of win7?

[Anna Tian]

Originally Posted by flotus1

mnabi how many CPUs (not the number of cores) are you talking about? And which specific version of win7?

I have 4 CPUs. I have no idea on which win7 version I'm having. But I'm changing to win server 2008 r2 now to support more CPUs now.

[mnabi]

Originally Posted by flotus1

mnabi how many CPUs (not the number of cores) are you talking about? And which specific version of win7?

The AMD 32 cores includes 4 CUP, with windows 7 Pro, 64 bit.
My win7 shows all cpu's there

[ghost82]

Directly from microsoft and reported on EULA:

Windows*7 Professional, Enterprise, and Ultimate allow for two physical processors, providing the best performance on these computers. Windows*7 Starter, Home Basic, and Home Premium will recognize only one physical processor.

I didn't know about this limit...

A server os should not have this limit.

[mnabi]

Originally Posted by ghost82

Directly from microsoft and reported on EULA:

Windows*7 Professional, Enterprise, and Ultimate allow for two physical processors, providing the best performance on these computers. Windows*7 Starter, Home Basic, and Home Premium will recognize only one physical processor.

I didn't know about this limit...

A server os should not have this limit.

I advise you to use windows server.

[ghost82]

Here we are talking about 4 cpus in one workstation, not spread across several nodes. As you can see your screenshot shows in the background 2 physical amd opteron cpus, which is the limit for 1 win7 pro workstation.

[evcelica]

So you got the 4 CPU workstation huh? What CPUs and memory did you get? Be sure to balance the memory channels evenly or performance will be garbage. I just benchmarked a quad CPU E5-4617 and it was slower than my single CPU i7 machine, because they used 6 DIMMS per CPU. 2 on 2 channels, and only 1 on the other 2 channels. They are upgrading it to use 8 DIMMS per CPU (2 DIMMS per channel) and I will benchmark it again and post those results, along with the i7 cluster and four other Dual CPU machines I have benchmarked.
So far the i7 cluster is mopping the floor with the other workstations. We will see how the Quad CPU machine does after they fix the memory configuration.

Going over 4 cores per CPU does not yield too good of results though. Going from 8 to 16 cores on a DUAL E5-2670 only showed a 16.8% increase in performance with double precision ON, I'm guessing single precision shows better scaling, which is what the ANSYS benchmarks posted on the website probably use.

We use Windows Server 2008 R2 on the quad CPU workstation.