How to get second NVIDIA GPU crunching?

[DrPop]

Alright...I give up. First time I've ever had 2 NVIDIA GPUs in one rig. BOINC says "GPU0 ...." all is good. By GPU1 it says "(Not Used)". What's up with that? I even tried adding a dummy plug to the second GPU, even though I've been told the CUDA cards don't need'em, but no dice.

So, what's the secret?

[Bryan]

So, what's the secret?

A couple of thoughts ... did you extend the monitor over both cards in the Windows display preferences.

I didn't have to do anything on my recent dual GTX 570 machine BUT there is a line you can add to a BOINC cc_config.xml file (the one where you tell it to report results immediately) etc.

<use_all_gpus>1</use_all_gpus>

This tells BOINC to use every GPU present.

[Maxwell]

<use_all_gpus>1</use_all_gpus>

This tells BOINC to use every GPU present.

3 to 1 odds say that's the issue. BOINC disables the weakest GPU in the system. If they are matched, both run. If not, the weaker one doesn't work.

Add that tag to your cc_config file and you should be good.

[DrPop]

Yup. You were right. Created a CC file and added that line. Working perfectly now.

While I'm at it, could you please give me the string to add in so it uploads the WUs as soon as they complete? That would be good to have on for challenges.
Thanks guys! Always coming through for us...I love this team!

[zombie67]

Yup. You were right. Created a CC file and added that line. Working perfectly now.

While I'm at it, could you please give me the string to add in so it uploads the WUs as soon as they complete? That would be good to have on for challenges.
Thanks guys! Always coming through for us...I love this team!

Just be warned, BOINC calculates the queue size based on the FASTER of the two GPUs. Using that string tells BOINC that you have two cards of the faster value. If they are too different, and you have a large queue size set, you may end of with late tasks.

The string you are looking for is:

<cc_config> 
<options> 
        <report_results_immediately>1</report_results_immediately> 
</options> 
</cc_config>

[DrPop]

Thanks much for that information, I didn't know that. I sure appreciate you keeping us mere mortals informed of all things BOINC related!
OK, so far in the DrPop rig I now have a GTX 465 and a GTX 275 both O/Ced to 800 core / 1600 shader / 800 mem. Do you think they are similar enough not to worry about anything?
One PCI-e slot left in my rig and one left in Kat's...

[zombie67]

OK, so far in the DrPop rig I now have a GTX 465 and a GTX 275

Those are plenty close. No issues being late. But if you threw in a 9500 GT, you may run into issues.

[Maxwell]

*cough*

[zombie67]

*cough*

While I'm sure I have read references to our FAQ page before, it never really registered. In fact, I'm sure that this is the first time I have ever seen the FAQ sub-link under Forum. Of course, I am oblivious to many..okay, most things.

But thinking about it, If I was new and looking around here, I would assume that the FAQ link would be to answer questions about the SETI.USA forum. Not to answer BOINC questions.

[DrPop]

*cough*

Lol! I even thought of doing a search, but then didn't really know what to call it. Thanks for that, glad to know we have it in there for all those new crunchers signing up to SETI.USA!