Hi, i got the 2010 iMac i3 3,06ghz with a ATI Radeon HD 4670 256 MB GDDR3 and 2x2GB of memory.

But i seem to only get cpu tasks, boinc says that there are no usable GPUs found.
Is this a bug from boinc? If it is, what can i do about it?

BOINC gets it's info from the card's drivers. See this FAQ

Ok, checked it out.. Downloaded BrookGPU, but guess what..
It has tons of files... and totally not user friendly.
Too bad. No wonder alot of people dont use boinc.

I don't see how it can be BOINC's fault that ATI/AMD in their infinite wisdom add a lot of files to one of their drivers. You can run most projects perfectly well on BOINC without it needing a GPU; the initial notion of BOINC is still true and used: run science on the idle time of your CPU.

Any and all tons of files in a driver isn't exactly a BOINC problem. BOINC isn't the manufacturer of the Mac, or any vendor's videocard or GPU or other coprocessor.
However, BrookGPU isn't a driver, it's the runtime/compiler program with which you can program GPU applications. You do not use it when you want to run work on the GPU. Had you read the FAQ Les pointed you at, you'd seen I pointed at it for a fuller (Wikipedia) explanation on what you were getting yourself into.

ATI has never been big in telling how to do anything, even programming applications for their GPUs meant people had to figure it out for themselves. I've been there and I have given up, just out of frustration.

But you don't have to program anything. All you have to do is make BOINC take notice of your GPU. All you have to do for that is install correct ATI videocard drivers and then restart BOINC.

Yet this is also true: "ATI does not provide CAL and Brook for Macintosh desktops or laptops. However, it may be possible to get the acceleration on a Macintosh desktop with an ATI Radeon GPU by running Windows with Bootcamp (http://www.apple.com/support/bootcamp/). VMWare, another software for running Windows on a Macintosh, will not enable your machine to access the GPU."

Still not BOINC its fault. Want to get ATI GPUs running on a Mac and you can't get it easily done? Yell at ATI. It's their GPU. Nothing BOINC can do about that.

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