GPU-Z 0.8.6 doesn't show CUDA for one of the GPUs on a quad Titan X SC setup

[TunaE]

I just noticed this...

I had four EVGA Titan X SC setup with SLI enabled, with the top GPU#0 feeding the 4K HDMI monitor, and NVidia Control Panel automatically assigning PhysX to (bottom?) GPU#3. In GPU-Z, of course the dropdown had four identical "NVIDIA GeForce GTX TITAN X" entries. I don't know if they really correspond to GPU#0...#3 in top to bottom order within the dropdown, but I'll assume so. CUDA was checked for #0, #1, and #2, but not #3. Why?

Then I went ahead and disabled SLI in the NVidia Control Panel, plugged the display into #3, which automatically moved PhysX to #2, but now GPU-Z reports that #0 doesn't have CUDA. Why was it #3, why is it #0 now, and why is it even thinking that CUDA is disabled on any of the GPUs to start with?

I am running the driver 361.43, but I first observed this under 359.06, then updated the driver, and am still observing the same.

I am using an ASUS X99-E WS 2.1 motherboard with EVGA 1600w PSU. For orientation: GPU#0 is the one installed closest to the CPU.

Yes, this happened across reboots.

 

[W1zzard]

No idea, GPU-Z creates a CUDA context and looks for the device by matching its PCI location (bus x, dev y, function z).

Can you test with a random CUDA app if CUDA is actually working?

 

[TunaE]

Oh, yes, definitely. Pretty much all I ran on this beast is BOINC projects, and it dishes out CUDA tasks from a number of different projects (SETI, Bitcoin Utopia, GPUGRID, POEM, MooWrapper, etc.) to all GPUs, and they all have been working. When BOINC Manager is initializing, this is what it reports:

12/22/2015 8:48:43 PM | | CUDA: NVIDIA GPU 0: GeForce GTX TITAN X (driver version 361.43, CUDA version 8.0, compute capability 5.2, 4096MB, 4025MB available, 7468 GFLOPS peak)
12/22/2015 8:48:43 PM | | CUDA: NVIDIA GPU 1: GeForce GTX TITAN X (driver version 361.43, CUDA version 8.0, compute capability 5.2, 4096MB, 4025MB available, 7468 GFLOPS peak)
12/22/2015 8:48:43 PM | | CUDA: NVIDIA GPU 2: GeForce GTX TITAN X (driver version 361.43, CUDA version 8.0, compute capability 5.2, 4096MB, 4025MB available, 7468 GFLOPS peak)
12/22/2015 8:48:43 PM | | CUDA: NVIDIA GPU 3: GeForce GTX TITAN X (driver version 361.43, CUDA version 8.0, compute capability 5.2, 4096MB, 4025MB available, 7468 GFLOPS peak)

 

[TunaE]

Incidentally, since you know the PCI location of each card, could you put that in parenthesis in the dropdown with the card names? This way, instead of having the same name four times, it would at least make more sense. Just a thought...

 

[W1zzard]

Incidentally, since you know the PCI location of each card, could you put that in parenthesis in the dropdown with the card names? This way, instead of having the same name four times, it would at least make more sense. Just a thought...

The tooltip for card name shows the PCI location. I didn't put it in the dropdown because it could confuse some less experienced users

 

[TunaE]

The tooltip for card name shows the PCI location. I didn't put it in the dropdown because it could confuse some less experienced users

Didn't know there was a tooltip on the other tab for the card name. Now knowing it, the order #0, #1, #2, #3 in the dropdown seems to correspond to Bus #10, #5, #6, #9, all Device 0, in that order. That numbering seems funny to me. I don't know if it is the right assumption to think the order in the dropdown is the physical order of the cards. These cards are on the #1, #3, #5, #7 slots of the ASUS X99-E WS 3.1 motherboard. I wouldn't have expected them be Bus #10, #5, #6, #9.

Is the order in the dropdown the order of the cards, or some other order?

In any case, this is what I am seeing: http://1drv.ms/1ZoX4L2. The leftmost card, which is listed as #0 in dropdown, which apparently is Bus 10 Device 0, is missing the CUDA checkbox.

If there is anything you want to run on my machine to gather further information, or if there is any debug info GPU-Z can create, just let me know.

 

[W1zzard]

This will be fixed in next GPU-Z build, thanks for the help!

 

[TunaE]

My pleasure...