GPU oddities

[1812]

Weird GPU issue

 

It appears at times, the GPU isn’t running "full" in the vm’s.

 

Card: EVGA GTX 760 SC

Computer: HP DL380 G6, dual processor Xeon E5520f, 24 gb of Ram (72 available), vm’s on cache drive.

 

when benchmarking, I get the following:

 

Cinebench shows between 22-28fps on the mac and the same on windows 10 vm. When I removed the card and put it on a bare metal machine with an i5-6600 and 8gb of ram, it scored about 125fps. For the longest time, I thought the drivers weren’t loading correctly in the virtual machines.

 

On the mac, using OpenGL extensions viewer, I was able to verify the nvidia drivers are loaded (contrary to what the nvidia control panel says.) The basic openGL cube testing shows an average of 420 fps on 720p, and 350 on 1080p on a single cube. Multiple cubes is obviously less, but never below 60fps. But it appears to be using the card to its fullest extent (or at least greater extent,) vs Cinebench not being able to do so.

 

Geekbench 4 API score (mac vm) for the card shows 39188 (is this good? I searched and couldn’t tell)

 

On windows vm, while watching a bluray mkv or hd youtube, a single core (of a multi-core vm) shows maxing out and causes video glitches. This was when running the machine as i440fx-2.3. After I switched to Q35-2.3 (same as the mac vm, it seemed to distribute the load across the cores and it didn’t happen anymore.

 

 

On the mac and windows vm it shows the pci interface on this card being x0. I’m sure this is a glitch? In unRaid,using lspci -vv, it shows the card connected at x8, which is correct for the slot it is in.

 

Other things I've done:

 

isolating cpus, using only physical cores, changing the number of cores, all does nothing to vary the score by +/- 5% in Cinebench. I looked around online and some people speculate that on the mac vm, power management limits the GPU based on the mac model number (3,1... 14,2, etc...) So I modified my simbios using chameleon wizard and used several different versions, but nothing changed the cinebench score.

 

So after reading all that, you're thinking "what's the problem?" Well, my concern is that is cinebench can't access the card fully using openGL and I'm trying to figure out why. And secondly, what other problems could this be an underlying symptom of having?

 

woo hoo.

 

 

[saarg]

Have you tried extracting the vbios from the card and adding it to the xml of the VM?

You can find the info in this thread

[1812]

I have not but will work on it.

 

Also, after updating nvidia drivers in the windows vm, cinebench refuses to run saying there is no openGL video card on the system... so perhaps an nVidia bug in both drivers with cinebench.

[1812]

tried the vbios. no change. windows 10 vm gives me a geek bench 4 gpu score of 45,500. Higher than the mac, but I don't know what that means in comparison to where it should be, or if that is where it should be.

 

[mikeyosm]

do you have hyper-v set to enabled in the VM properties? I suffered from serious CPU degradation issues in 6.1.9 and I have a Xeon 2660 V3 10 core processor. 6.1.2 seemed to have resolved the majority of my performance probs.

[1812]

Doesn't seem to affect anything whether enabled or disabled.

[dinoaus]

I was having issues with GPU performance on 6.1.9. Just updated to 6.2 RC5 and getting way better performance. Using a GTX 1070.