First off, I’ve only just joined this forum, but it looks like an awesome place, good work.
Now, I’ve been trying out Cycles but I’m having trouble getting it to render using my GPUs. My Macbook Pro - the last model before they introduced i5s and i7s, 
- has two graphics cards, and they both show up under ‘Compute Device’ in the preferences when I click OpenCL.
But when I render/preview there is no noticeable increase in speed and my CPU decides to start boiling water (105 degrees is around about the highest I saw it get, 0_0).
I tried looking around the forum for any info on this, but I didn’t come across anything much.
Am I doing something wrong? I assume my cards are supported. I heard something about CUDA drivers or something like that, is that something to do with it? The fact my cards showed up made me assume that it was all a-OK, I’m just not getting the results.
Thanks for any help.