B85M-E/CSM for 2 GPUs?

[foldy]

FahBench also has a UI and you can start it multiple times concurrently then configure each for a different GPU and run them all or which you want. The tool msi afterburner also shows pcie bus usage. Each pcie slot has its lanes exclusive and as soon as you put in more GPUs the other pcie slots get reduced from 16 to 8 or 4 lanes independently of GPU bus usage. There is only one exception: When the mainboard has a PEX switch chip then the pcie lanes are dynamically used by all slots meaning even with 4 GPUs each can use up to x16.

But maybe we split this new discussion to the PCI-e bandwidth/capacity limitations thread
viewtopic.php?f=38&t=28847&start=75

[bruce]

What happens of you start two copies of FAHBench?

[Aurum]

What happens of you start two copies of FAHBench?

I tried to install it on a PC with two identical RX 470s but it won't run: api-ms-win-crt-runtime-l1-1-0.dll is missing.
I tried Repair, unistall, install, repair. Same.

[foldy]

There is a FahBench release note about this error with a potential solution.
https://fahbench.github.io/releases/v2. ... s-msi.html

[Aurum]

FAHbench works great on other PCs. I launched 4 instances and they have a pulldown for device so you know which one you're selecting. The rig I tried is not a suitable testbed, uses 1x risers, etc. I did see that the Creating Context step runs at random speeds on different devices, first time I tried it the 4th device started benching first and the 1st device last, The next time it was vice versa. So I set the test time to 1,000 seconds and started them. By the time the 2nd & 3rd devices started benching the 4th device was at 9% and 1st device was still Creating Context. When 1st device started benching the 4th was at 27% and the 2nd & 3rd devices were at 19%.

[foldy]

Creating Context uses one CPU core, so if you start 4 concurrently make sure you have 4 CPU cores idle.

[Aurum]

There is a FahBench release note about this error with a potential solution.
https://fahbench.github.io/releases/v2. ... s-msi.html

Thanks, that fixed it. Her W7-64 was up to date. The link on that page is only for Win10. For all earlier versions:
https://support.microsoft.com/en-us/kb/2999226

[Aurum]

Creating Context uses one CPU core, so if you start 4 concurrently make sure you have 4 CPU cores idle.

Good point, Rig-1 only has an AMD Athlon II X2 250 with 2 cores. My idea was to let the bench run so long they all converge on their stable values.