As many of you already knows running Moo with a dual+ gpu hw with the latest boinc client is really complicated. We have the following possible scenarios:

1- revert to BOINC 6.xxx thus losing any openCL capability.
2- do nothing: tasks are downloaded but never start.
3- app_config with <gpu_usage>1.00</gpu_usage> (I tested it on a couple of HD6950 and noticed a *huge* performance drop)
4- same as above but also adding <max_concurrent>1</max_concurrent> (this works but *only* if Moo is the only gpu project you run)

The problem is that, regardless of the configuration you use (3 or 4) a Moo workunit will always notices that you have a dual gpu setup and tries to start two "crunchers" (in the third scenario the result is 4 threads fighting for just 2 gpus). This is something that comes by design from the original dnetc.com client. I don't think that something can be done here, by the Moo administrators, for solving this....

But having the source code of the client and a little bit of knowledge and time to spent (that I don't have by now....) shouldn't be too difficult to just insert a couple of lines in order to completely disable the multithread capabilities of the client, thus solving a lot of problems here.

Running Moo out of the box is getting more and more complicated... The lack of proper support of the latest AMD Tahiti (and newer) gpus and problems like the one I just described above are continuously pushing away users from this project...

I run Moo! on different boxes, with different experiences:

1. Ubuntu 13.10 box with APU and two GPUs, using Catalyst 13.4, running six WUs at a time;
2. Win8.1 box with APU and one GPU, using Catalyst 13.4, running four WUs at a time;
3. Lubuntu 13.10 box with APU and one GPU, using Catalyst 13.4, refusing to download work: 'don't need';
4. Win8.1 box with both AMD -HD 7790, using Catalyst 13.4- and nVidia GPU, refusing to download work: 'don't need'.

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Or you could use a cc_config.xml file like this:

<cc_config>
<options>
<use_all_gpus>1</use_all_gpus>
<exclude_gpu>
<url>http://boinc.fzk.de/poem/</url>
<device_num>0</device_num>
</exclude_gpu>
<exclude_gpu>
<url>http://moowrap.net//</url>
<device_num>1</device_num>
</exclude_gpu>
</options>
</cc_config>

And just exclude one of the gpu's from Moo, the file above excludes gpu zero from Poem and gpu one from Moo. You can use any projects url, gotten from its home page where it gives you the address in case it isn't listed in the list of projects.

Thanks Mikey for your hints. I will try this later, and report back, even if I have the bad feeling that the Moo tasks will use both gpus regardless of the boinc configuration... we'll see.. Anyway, do you agree with me that this kind of micromanagement is far too complicated for the casual user?

Thanks Mikey for your hints. I will try this later, and report back, even if I have the bad feeling that the Moo tasks will use both gpus regardless of the boinc configuration... we'll see.. Anyway, do you agree with me that this kind of micromanagement is far too complicated for the casual user?

Yes, I think it should be built into Boinc as the software already detects when people have multiple gpu's in the machine! There is no reason the software can't ask you what project you want gpu zero to crunch for and the same for gpu 1.

Provided you can download GPU WUs for your system -does not seem to work with HD7xxx GPUs- you can easily crunch more at a time by setting the right parameters in the app_config.xml, but you need to modify (in case ot two GPUs)

<gpu_usage>1.00</gpu_usage>
to
<gpu_usage>0.50</gpu_usage>

and

<max_concurrent>1</max_concurrent
to
<max_concurrent>4</max_concurrent

With three GPU the last line becomes <max_concurrent>6</max_concurrent

---

Provided you can download GPU WUs for your system -does not seem to work with HD7xxx GPUs- you can easily crunch more at a time by setting the right parameters in the app_config.xml, but you need to modify (in case ot two GPUs)

<gpu_usage>1.00</gpu_usage>
to
<gpu_usage>0.50</gpu_usage>

This change means you will run 2 units at once, putting 0.33 means 3 units at once and putting 0.25 means running 4 units at once. Not all gpu's can handle this and if you don't also leave a cpu core free, crunching can actually go slower as the gpu will be waiting to be fed.

and

<max_concurrent>1</max_concurrent
to
<max_concurrent>4</max_concurrent

With three GPU the last line becomes <max_concurrent>6</max_concurrent

This has been debated as too whether you should include the cpu cores you have or not, personally I do not use the setting and it works for me in my dual gpu setup.