x850xt OCing troubles

I recently purchased an Sapphire x850XT PCIE(newegg). I've been using ATi Tool to OC it thus far and have gotten up to 555/560(stable with no artifacts) at 58C Core and 49C Ambient without modding any volts or timings. Now attempting to go past 560/560 I was getting artifacts. Normally I would've just assumed it was my stock cooling, but one of my friends also bought this card and he lives up in MA with 56/40C temps and cant seem to break this 560/560 barrier as well.

We've been trying to work through this(overhanging fans , colder AC etc), but haven't been able to do much about it

Is this purely because these temps are too high? ( I saw much higher so I don't think that might be the problem) Or is this a volt or timing problem. Or last and hopefully not the cause -are our cards just from a bad lot.

Any ideas?

Thanks

stock volts only gets you so far. even if you could get your temps down another 10C, you might only see another 10 MHz without increasing mem, gpu or chipset voltage.

Can you mod volts through software?
And if so- how dangerous is it?

And thanks for such a fast reply

Im having trouble oc'ing my X850XT as well although im on water and my freq has hit 584 on find the max core freq in ati tool but i heard beeps from my system and locked up and tried it again - same thing. I have been able to hit 594 on my ram but it wont seem to go any higher and beeps if i try to increase the freq beyond 594 so im stuck like our new member here perhaps you have a cooling probelm? i have no idea (logical guess would be the voltage since its at stock Vcore)why im being limited but ive seen viper johns pics of 600core+/650+ram clocks... that is some wicked OC'ing on air and water.

Your card is just maxed out, an aftermarket heatsink might give you a little boost.Theres a simple pencil mod for the X800's but I don't know if you can do it on the X850 i'm guessing you can. I wouldn't vmod with stock cooling though.

Scott.

Ahhh.. - that sucks . Perhaps I'll be brave enough to vmod it sometime.

I really appreciate the input though.