First time forum poster, long time SETI geek... :-)

Background story is that I'm currently running 24/7 a self built Windows machine with an i5-4690 cpu, Z97 motherboard, and a GTX 770 GPU. Just for fun, I was thinking about adding a second $100-ish GPU to devote to SETI. My motherboard can support another video card, my power supply is big enough, and I have a beast of a full tower case with extra cooling fans.

My questions is - Would BOINC be able to make use of the second GPU if it is not a GTX 770? I'm open to other suggestions, but I was considering adding a GTX 750 because it would be around 60% as fast for 1/3 the cost of the current equivalent of a GTX 770 (my object is to get the best bang for the meager buck).

This is where I get the 60% as fast figure - https://setiathome.berkeley.edu/gpu_list.php

For what it's worth, I'm not into the competition / bragging rights aspect. It's just for fun and the idea that I'm doing my part to help the dream of finding E.T. come true (actually chocking back a few tears as I type this). Thanks!!!

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If the 2nd GPU wasn't of the same speed (assuming it's from the same vendor), Boinc wouldn't use it by default,
But you can override that with the <use_all_gpus> cc_config.xml option:

Client configuration

<use_all_gpus>0|1</use_all_gpus>If 1, use all GPUs (otherwise only the most capable ones are used).

If the 2nd GPU was from a different vendor, ie ATI/AMD or Intel, then you may need to connect a 2nd Monitor, or extend the desktop instead.

Claggy

Yes you can but you need to add like a cc_config.xml to Bonic folder


<cc_config>
<options>
<use_all_gpus>1</use_all_gpus>
</options>
</cc_config>

That way it will use both of the GPUs


If you don't know how to make a xml please post and we can walk you thru it and how to find where to place it

Zalster

As the others have said, setting <use_all_gpus> to 1 in your cc_config.xml file works a treat.

As for mix 'n match GPUs I think the received wisdom is to stick with the same manufacturer at least. I have a Titan and 2 x 750Ti and everything is ticking along nicely.

The trick is to make sure you also tune the app_info.xml file too. There's plenty of info floating about on how to do that but if you want a condensed and probably shoddy explanation of it all then I'll see what I can knock out for you this evening. In a nutshell as ALL the graphics cards use the same settings (though this might change in the future apparently) you need to set the workload to something sensible for the lowest powered card.

In my case 2 WUs per card is the sweet spot, the Titan could probably stand to do 3 or 4 but not the 750Ti so running at 2 gives the most work per unit time, if that makes sense.

I like the 750Ti, for what it's worth, the price/performance (not to mention low LOW power consumption) is an all round winner for me.

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~W