Quote Originally Posted by dejanh View Post
Personally I never had to up the IOH or ICH voltages. Indeed, I run them at lowest possible settings they can be set at...I owned a R2E before, now own a R2G and E759 Classified, but the R2G and R2E are the same board basically, -1 PCI-E slot. The behavior and settings are the same across all of my boards. Never had to fiddle with IOH/ICH. Are you setting your PCI-E clock higher than 101MHz? If you are you need to back down the PCI-E clock to 101MHz. Also, how have you actually verified your general CPU overclock stability? Are you actually 100% stable at that clock? Finally, are you sure your PSU is up to the task to feed such a high CPU overclock combined with two HD 5870s?
I am not setting the PCI-E clock any higher than default. It is completely stable at 4.6ghz using the bottom 5870 only. The PSU is a 1000 HX Corsair..plenty of overhead room left.

affiliate13 earlier mentioned that he had to up his PCI-E voltage a little..I'm awaiting word on what setting I should start with. I have seen other posts with people manually setting their PCI-E voltages a little higher than the "Auto" setting. The Crossfire 5870's only stop responding when I go above 210 BCLK...and the BOTTOM 5870 continues to work no problem. Therefore this would lead me to believe that there is not enough juice going to the PCI-E when upping the BCLK as one of them will still run no problem.

I am however always open to suggestions...as I am fairly new in the i7 world of O/Cing