I've updated the optimized miner to b15. This version currently works only on Linux - I would greatly appreciate some help figuring out what I broke on windows/mingw! I've left the b14 binaries for both linux and windows online.
Btw - you want to run this with a larger sieve. Try various values, but I find that two billion works pretty well ( -s 2000000000 )
I'm boosting the default from 500m to 900m to be conservative, but 2b is typically better.