Bad overclocking..PSU?

[AbyssDemon]

Greetings

I have an sapphire x1800gto and i've discovered that when i overclock the gpu i can go to 612 mhz stable at 1.2 v (74º C on the gpu, 4 hours of atitool with no artifacts). When i overclock the memory i can go to almost 700 mhz @ 2.1 v (495 mhz stock) (i didn't try further). If i put the two of them together (gpu + mem), both atitool and ATT go crazy finding artifacts after a few seconds. It seems my PSU can't handle much... Right now i've to work at 560/612 core/mem @ stock voltages and it seems to be stable (2 hours of atitool scan) .. However ATT still artifacts after 1000 - 1100 seconds.

Could it really be the PSU? I find it strange...550 w and 34 amp in the +12 rail (+12v1=16 amp ; +12v2=18 amp), should do more than enough... The gpu is cooled by an zalman vf700 cu.. so taking the temperature away it only leaves the PSU..right?

[RobsX2]

Originally Posted by AbyssDemon

Greetings

I have an sapphire x1800gto and i've discovered that when i overclock the gpu i can go to 612 mhz stable at 1.2 v (74º C on the gpu, 4 hours of atitool with no artifacts). When i overclock the memory i can go to almost 700 mhz @ 2.1 v (495 mhz stock) (i didn't try further). If i put the two of them together (gpu + mem), both atitool and ATT go crazy finding artifacts after a few seconds. It seems my PSU can't handle much... Right now i've to work at 560/612 core/mem @ stock voltages and it seems to be stable (2 hours of atitool scan) .. However ATT still artifacts after 1000 - 1100 seconds.

Could it really be the PSU? I find it strange...550 w and 34 amp in the +12 rail (+12v1=16 amp ; +12v2=18 amp), should do more than enough... The gpu is cooled by an zalman vf700 cu.. so taking the temperature away it only leaves the PSU..right?

Well it does indeed sound like your psu to me. I used to have pretty much the same problem as you are experiencing and it ended up being my psu. Let me tell you that for one thing Dual 12v rails is not always a good idea because you cant be gaurenteed how the amps are going to get spit up in the system, in some really bad cases the 2nd or 1st rail gets completely ignored leaving you with only 16 or 18 amps for the whole system.

The latter ended up being my problem and after doing some research I found it best to get a good strong single 12v rail PSU with a ton of amps on it. I purchased a 560 watt Silverstone Zeus PSU with 38 amps on a single 12V rail and this thing has my Dual X2 4800@2.8 ghz, my ddr400 mem at 460mhz and my X1900XT@730 core and 832 mem

The rails are rock stable on this PSU and it could be pushed even further if needed, I will never ever again skimp on a PSU purchase.


As of right now I have a pcpowercooling 60amp single 12v railer on the way to get me ready for a couple of DX10 cards so I am selling my Silverstone PSU which is only 3 months old but in otherwise new condition.