Quote Originally Posted by overclock View Post
My HIS 4870 1 GB sucks : it is cooled by a phase change cooler, at -38°C (core temperature) and in 3DMArk06, it is stable at 951 Mhz max (1010 Mhz for the RAM). And the games are stable from 895 (Condemned) to 970 Mhz (hellgate). Most of them are stable at 920 Mhz. Pretty bad since I expected a 40 % overclock like my previous 9800 GTX. Here, I obtain around a 20 % overclock. Since the memory IO is far hotter than the core (between 10°C and 15°C more), checked with Riva Tuner 2.11, I assume that the memory controller is limiting my overclock ability. Since it is a 1 GB card, the memory controller might be stressed more than with 512 MB ?

I will sell it and buy a 4870X2 instead. I don't want to buy a second 4870 1 GB and obtain such a crappy overclock again.
Well you can't compare percentage overclocks 1:1, Nvidia architecture tends to scale to higher frequencies with less gain. I think if you did a performance scale comparison you would find that the cards overclock about the same. Its a shame you cant reach for 1ghz @ benches. I think the Issue is OVP @ 1.5v on these cards although we don't want to start killing them.