Don't use that I used 128 for a couple weeks before diff. went up and they did well averaged 1020gh each and now I have them at the default 256 and still humming right along at 1000+gh. they didn't seem to do very well at that higher setting. Also if got the ones with the single 235cfm jet engines I found a really nice 105cfm sanyo fans that that keep them right around a 60c average. If your only getting 29 gh then we are not talking the same machines or you got a problem. they should be doing 1Th easy.
Sanyo Denki 109R1212H1011, 120x38mm-3pin TAC Sensor, Hi-speed 2600RPM, 102.5cfm