I am setting up a new PC, and find that on the GPUGrid Preferences web page, the "Use Central Processing Unit (CPU)" checkbox always reverts back to enabled (i.e., checked) when I click on "Update preferences", even though I have set it to disabled.

I am setting up a new PC, and find that on the GPUGrid Preferences web page, the "Use Central Processing Unit (CPU)" checkbox always reverts back to enabled (i.e., checked) when I click on "Update preferences", even though I have set it to disabled.

On this project, the only applications available are those for NVidia GPUs. Make sure

Use NVIDIA GPU 
Enforced by version 6.10+	yes

is checked, otherwise you'll do no work at all.

With that checked, I think you'll find that it is possible to de-select 'Use CPU' - although, without any applications (except the forthcoming Android apps), it won't make any difference.

Note that all applications, even those primarily intended to run on a GPU, require some CPU time as well - the amount depends on the graphics card, the operating system, even the GPU driver version. You can't escape CPU usage entirely, and you can't control exactly how much CPU time is needed.

Use NVIDIA GPU 
Enforced by version 6.10+	yes

is checked, otherwise you'll do no work at all.

With that checked, I think you'll find that it is possible to de-select 'Use CPU' - although, without any applications (except the forthcoming Android apps), it won't make any difference.

Yes, of course. But the problem is as stated above. It reverts back to unchecked.

It is probably related to an error message I see in BOINC 7.3.2 that my pc is not set up to accept that type of work, even though I have two GTX 660s installed. So that may be triggering the GPUGrid preferences page to try to send me CPU work (?). At any rate, I will change a few things around on my PC and try again; it could be a BIOS setting that is preventing the cards from being used, even though the drivers install properly.

EDIT: Problem partially solved. I had set the motherboard to use the internal graphics adapter; that works on some motherboards while still allowing the PCIe cards to functions, but not others. So I switched it around to make the PCIe cards the primary graphics adapters. So GPUGrid probably thought I did not have a GPU card at all, as you suggested Richard.

But I still can't change the Preferences page to remember the setting not to use the CPU; maybe I have to try another profile or something. I will work on it.

Use NVIDIA GPU 
Enforced by version 6.10+	yes

is checked, otherwise you'll do no work at all.

With that checked, I think you'll find that it is possible to de-select 'Use CPU' - although, without any applications (except the forthcoming Android apps), it won't make any difference.

Yes, of course. But the problem is as stated above. It reverts back to unchecked.

It is probably related to an error message I see in BOINC 7.3.2 that my pc is not set up to accept that type of work, even though I have two GTX 660s installed. So that may be triggering the GPUGrid preferences page to try to send me CPU work (?). At any rate, I will change a few things around on my PC and try again; it could be a BIOS setting that is preventing the cards from being used, even though the drivers install properly.

Sorry, I didn't check far enough. The upper

Use CPU 
Enforced by version 6.10+	no

on the preferences page can be de-selected, but the lower

Use Central Processing Unit (CPU)	yes

at the bottom of the page can't - I think that must be the one you're talking about. (that's older, deprecated, code anyway).

In any event, it doesn't make any difference. No, the server code on the preference page doesn't change things around in response to client errors - it only reacts to your input via this web site. If you're getting error messages, it's best to post them in Number Crunching and let the guys there try to work them out.

Thanks. To clarify, when I was using the internal graphics adapter, I could not download work at all, and got that error message on BOINC 7.3.2 that I did not have a suitable PC. Now that I am using the PCIe cards as my primary graphics adapters, I can download work and don't get the error message on BOINC (though that may be because I went back to BOINC 7.2.39 as a precaution).

At any rate, that may have somehow confused GPUGrid that my PC could not handle graphics work, though I hope it will correct itself after a while. But they may be two separate problems that will take more action to fix. I will just let it sit and maybe try a new profile later. Thanks for jogging me on that possibility.

EDIT: Maybe it is good enough that "Use CPU, Enforced by version 6.10+" is not checked? That works OK, though I now don't know what the other CPU setting is for. At least I have not gotten any CPU work yet, and don't see it on the Project Status page anyway.