A problem running 4x Tesla C2075 on TyanS7025 Any CUDA computation is extremely slow.

I’ve got a problem running 4x Tesla C2075 on motherboard Tyan S7025AGM2NR under Windows 7 64-bit Professional. At the beginning I was unable to successfully boot up the operating system. I found and flashed the very last BIOS v1.08. Now the system boots up correctly, but suffers from poor user action responsiveness (e.g. starting application) and when running any CUDA computation on single GPU it is extremly slow. It is the same for DeviceQuery example from SDK where listing of all device properties takes 13s (i.e. 3s per devices, but when there is only 1x C2075 it is instant). VGA output is provided by onbord VGA AST2050 and all GPUs run in TCC mode.

I’ve contacted mainboard manufacturer, but his answer was it is usually a driver problem. So I’ve changed drivers but without any significant effect.

Server configuration: Tyan S7025AGM2NR BIOS v1.08, 2xCPU Xeon E5530 @ 2.4GHz, 12GB DDR3, 4x Tesla C2075, Windows 7 64-bit Professional (clear installation, all updates installed), NVIDIA Driver 285.67, CUDA Toolkit 4.1 RC1, power supply 1350W

Does anyone observed the same behavior?

Thanks for help.

Note: This problem is identical for 3x Tesla C2075.


I am suffering the same problem. Mine is a Tyan 7015 with 8Tesla C2075, 8Xeon E5620 2.4GHZ, 48GB DDR3, Win7-64bit. Extremely slow.

I took down 7 Tesla cards and the response time is almost normal. However, I ran the NVIDIA example and my C2075 is not working correctly. I cannot run some of the examples. When plug in 8*Tesla cards, the GPU driver process crashes down the OS.

Have you solved the problem? I am planning to install Ubuntu instead.

Yes, I still have the problems. I’ve contacted NVIDIA support and TYAN support and asked them both for a help.

Hi, pleas try this:

Go in to BIOS and change the following:

Advanced -> PCI Express Configuration -> Active State Power-Management [Disabled]

Chipset -> CPU Bridge Configuration -> QPI L0s and L1 [Disabled]

Both are disabled as you suggest. Enabling QPI L1 made the issue worse.

Anyway thanks for help.

Have you tried to run the system with the monitor plugged in to one of the Tesla Cards instead?

Yes of course, no performance effect. But there was an side effect of screen blinking (irregular) with three blue/black lines in the middle and over the full width of screen. That’s probably because of the card providing a video output was also used for cuda computation.


that sounds like a bad card. Try to remove that card and test another one running the monitor over.

svjezii, tianren - could you solve the problem ? My Tyan-based system has almost similar one - extremely slow when 8 GPUs are plugged.


thanks to TYAN support I’ve already closed this issue, but didn’t post the solution here. I’m sorry for that. The key is to decrease the maximum available memory for Windows to at least 1GB less than it is installed, to the benefit of hardware reserved memory that is reserved for use by the BIOS and some drivers for other peripherals (some info about memory allocations http://support.microsoft.com/kb/978610). You can see this memory organization in Resource monitor.

Step by step tutorial is in attached document.

In my case, it simply worked.

I hope this will help you.

Solution is found, thanks to Tyan support. It is a bug in Win7, system has problems related to RAM counting.

Say, there are 72 gigabytes of RAM installed.

  1. Run “msconfig”
  2. Click “boot” tab
  3. Click “advanced” option
  4. Check the “max memory” box, the max memory field will automatically put “73728” (72GB)
  5. Enter “72704” and apply the changes, restart the system, the system will run at what appears to be normal speed

The key basically is to change the max memory from whatever it shows to 1GB less than what it shows (subtract 1024).
This will insure proper operation of the system regardless of the total amount of memory installed.

Yeah, I have also got the answer from Tyan describing the same solution, thank you anyway! You are mentioning some attached file … attached to what ? Don’t see any links or something like that.

Sorry, the file needs to be attached explicitly, not only by its selection. Here it is.

Win7 + 8x C2070 + FT72-B7015 Configuration.doc (604 KB)