MrTeal,
how is higher voltage affecting temperature of dies.
We have summer time and temps are around 30 degrees C. I'm using H100i with SUNON fans and all I can do is piss poor 525MHz

Previous owner set voltage to 0.91V and he run it at 930MHz or something like that. I can't run that high.
My other two Habs have cheap china water blocks and they run on 750MHZ--0.86V.
Can this higher voltage cause higher temps of dies ?
Thank you very much
Higher voltage will affect the power consumption, so it would be worth dropping the voltage. I find 910mV (shows up in cgminer as about .86 at the die) to be good for around 800mV. I would look at taking off the cooling head, cleaning everything good with isopropyl and reapplying the paste though. Unless the fans are extremely low flow, you should be able to get higher than 525MHz without overheating.
What's the model number of the fans?
Board is bent a bit 2-3mm and paste was re-applied 3 times. First I have used Paste supplied by by Corsair and then MX-2.
Fans are PMD1212PMB1-A.
Sometime temp drops for a split second down to 60-70C and then back to 100C.
I don't have Shitnux to lover the voltage

Isn't there any cgminer command I can use to force voltage down ?
Thank you very much for your help
Something is wrong there. Have you tried looking at the individual die temperatures using the PepperApp? Unless your ambient is 50C or higher, you should not be seeing overheating with two 200CFM fans. I wouldn't break down your other boards, but do you have another water cooler (even a small one) you can try in place of the H100i? Properly applied even an H80i should be good up to ~900MHz using a fan like that.
JakeTri posted a cgminer version that allowed you to set the voltages, although it wasn't merged into mainline cgminer.
Ambient is 31C, exact number of fan is PMD1212PTB1-A 4800rpm 150cfm.
Dies are as follows:
ASIC 0 = 93
ASIC 1 = 98
ASIC 2 = 101
ASIC 3= 102
537 MHZ and 0.91V. Corsair H100 is brand new so would think that it's working ok. Pump has 2 small cables- one is for powering pump and second is unplugged.
I tried to plug that one to a Hab board port "PUMP" and it made no difference. I have tried to put fans to FAN 3,4 connectors and Pump,Fan 2 connectors and that made no difference. Cgminer command has "--hfa-fan 100" so it should make no difference which FAN port I'm using. I even tried to install Corsair V2 software on my Win7 to see if I can get any data for pump speed(it doesn't show anything).
MX-2 paste isn't bad but I might try liquid metal as I have used on my other 2 hab boards(run out so had to use what I had).
Had a look at Cgminer from JakeTri and in Read ME file I can't see any voltage settings
