zefir,

One other question here: are there known PLL settings for faster speeds?

I ran a quick test (submitting 101 jobs to the four chips as fast as they could take them and then checking that I got all six of my nonces out of each one) and things looked good (no errors and came out right at 25GH/s).

I need to run this for longer of course to be sure, but I need to get the cooling going for that.

I'd also like to try pushing the chip clock rate for a short run, perhaps seeing if I can get to the 40GH/s turbo mode. I assume that's computed based on a 1.25GHz system clock so for my 12Mhz reference clock I would need an effective multiplier of 104.

I tried manually running through your set_pll_config code for this but the result didn't come out so well (I might very well have done this incorrectly). I wasn't quite sure what the extents of the various fields are as the data sheet looks to be different to your code (and to the various PLL settings posted).

Thanks for your help!