52 Amps not enough for 2900pro?

[Jakalwarrior]

When I overclock past 800 core I run the risk of crashing. I was wondering what was causing this and once while running at 860 core CCC had a pop up telling me "your power supply does not support this card, your clocks have been lowered" I also notice it defaulting to some lower clocks sometimes instead of crashing. Is 3x 18amp 12volt lines not enough? Only other things I have running are my processor at 1.3vcore, 1 raptor, and a few fans. (it is solid at XT clocks in Crysis with all "very high" settings in XP, just cant push the core :/)

[roger_h99.nor]

You're probably not using a 8-pin power connector?

[Jakalwarrior]

Nope, no 8 pin. That is just two more grounds though isn't it? Most people told me it wasnt neccessary and wouldn't really matter :/

[MadDias]

ur right... 8pin doesn´t matter cause it´s indeed just adding 2ground wires. i´ve got a ocz700w gxs without the 8pin and a zalman zm850-hp with the 8pin and both psus make my cards clock the same way.
3x18amp on 12v+ isn´t 52amps in total.. it´s a lot less
650w should be more than enough to fire a single 2900pro.
maybe ur gpu needs a little more juice over 800mhz. did u try upping the vgpu with atitool or a modded bios?

[Jakalwarrior]

Ooops is 3x19amp lines. Anyway, I havent tried any more voltage since I dont think ati tool really changes it and bios flashes on video cards scare me lol.

[spajdr]

Well .. ati tool should support it, you dont need to flash it, just raise voltage and do some testing, wouldnt hurt to pump up some more voltage into card.

[Jakalwarrior]

How much voltage is safe on these cards?
Im not getting any artifacts though. When it gets too high it either downclocks its self to 500/500 (lower than stock) or I get a hard freeze :( Temps in the 70s or lower though.