7870 Overclocking

[Grnfinger]

I have a pair of Sapphire 7870's

Currently there on air and looking to overclock them to see what they can do.
Have no desire to kill them so what would be my MAX SAFE volt increase?

[buildzoid]

it should be the same as for any other 7xxx series cards as they are all on the same manufacture process so 1.25v though if Sapphire is anything to judge by then 1.35v should be just fine but I very much doubt that all GPUs will survive that as Sapphire uses it on there Toxic highly binned cards. Also most reports say that anything over 1.3v doesn't help overclocking so 1.25v is probably ideal if you can cool it. Also check you ASIC quality low (<60)is for extreme cooling(LN2) and takes a lot of voltage to kill and overclock over 1.4 to fry instantly. If you have high(>70) quality the go with less voltage like 1.2v.

[DarkOCean]

First oc them as far the stock voltage lets you, they do pretty well on that you know.
If they are ref cards i think you should limit to stock voltages, it should be good for at least 1150/5500.