Now, that’s weird: installed 2.71 instead of 2.70, and now there is no way to choose between CPU and GPU when rendering with Cycles. No idea why, it was there with 2.70 and worked okay. So it’s very improbable that the problem is with hardware. Now there’s “open shading language” option only. Any kind suggestions what might be wrong? Screenshot is below:
UPD: Kind people helped to sort it out.