Quote from: MrTeal on June 06, 2014, 02:47:40 PM

Quote from: SVK on June 06, 2014, 10:03:34 AM

Finally managed to fire up one board (was making frame for it) and noticed that 850MHz gave me around 630GH/s then I have tried 900MHz and it gave me 600GH/s.?

Not sure if it is my PSU or Voltage. Voltage was 0.86.

Try running the Pepper app. What you'll see if you go too high with insufficient voltage is that dies start stalling, and the temperature will drop.
I got these from gateway last night, so I'm pilfering them but attribution.

This is a board at 950MHz, with different voltage setpoints.
930mV
https://peppermining.com/wp-content/uploads/2014/06/930mV.jpg

940mV
https://peppermining.com/wp-content/uploads/2014/06/940mV.jpg

950mV
https://peppermining.com/wp-content/uploads/2014/06/950mV.jpg

970mV
https://peppermining.com/wp-content/uploads/2014/06/970mV.jpg

You can see the temperatures drop constantly at 930mV; the chip is being starved for voltage. It's much better at 940mV, and at 950mV three of the dies are running fine. At 970mV they're all running good.
With the python script gateway posted you can even adjust the dies individually. For the above case, you could do
./hftool.py -w 0:950@950,1:950@950,2:950@950,3:970@950
That would set the first 3 dies to 950mV and the last one to 970mV

Note that cgminer overwrites the frequency value (the number after the @) with it's setting, unless you use --hfa-hash-clock 1
That can be useful if you're really trying to push the board. You might end up with a die that just can't do 950MHz even at higher voltages, but the other three can get up to 1GHz. If that's the case, you can set the defaults for that board individually and run some of the dies faster than the others.

I've tried getting this to run on windows with no luck. I get 'HFBulkDevice not found' in a loop. Does this only work on ubuntu? I'm unable to get past ~875 at the stock voltage. Sad

Is hftool the only way to adjust voltage?

Right now I'm running:

https://i.imgur.com/HOUkBDk.png

Anything above this and I get fluctuating temps like gateway demonstrated.

Thanks, great boards btw!