Voltage drops, normal?

Hi guys,

I have been having a issue with my graphics card crashing and I have found the only way to keep it stable is to underclock the memory clock with rivatuner. But I have been keeping an eye on the hardware monitor and have noticed the supply voltage is dipping occationally as well as the fan speed and fan duty cyle. Often the dips are happing at the same time but not allways. I just saw the voltage dip from 3.33 to 2.11. Could this be whats caursign my crashes?

Spec

qt 8800
Q6600
corsair tw60w
corsair xms2 8500 2x1GB

-voltage drop is one of the differences between a good power supply and cheep one.
I'm not sure graphic cards use 3.3v, I thought they only use 12v.
If your 3.3 is dropping your 12v is probably also dropping, witch could cause a crash.

When I say dip, I mean like a spike. looking at the logs, its gone as low as 0.83. I had the same problem with a card i returned that was with a cheapo PSU, i got a good PSU to aviod these issues :-S. This card has been stable for ages but its suddenly havning problems. At the moment the GPU is 49C. when stress testing the card i have gone upto 70C whilst underclocking and thats the highest ive seen it. But it's crashing often at something like 55C so I dont believe its a heat issue. Is it possible i could be having power flucuations in the house it's self?

only seems to be dipping whilst running something graphic intensive

All voltage swings I have ever had was the power supply.
Even Corsair can't be 100% perfect.
The only way to tell for sure is by trying another power supply, or your vid card in another computer with large enough power supply

Edit; you could also try your power supply in another system with a demanding vid card.

Ah the irony, the fancy PSU I got in order to have a stable system is faulty and the cheap ezcool PSU that cost me 25 pounds refuses to crash, lol. Thanks for your help guys, problem FINALLY solved.

Once i maxed out the settings, i got some more dips and crash but i guess that could be because it isn't a powerfull unit, 450w i think it was

I under estimated corsair.
here is a 650 single rail, it has 52 amps on the 12v rail.
that's why I/m not a fan of more than one 12v rail, the individual rails aren't big enough for some vid cards. some cards, you can plug in 2 rails, but i think not many can.

edit; http://www.newegg.com/Product/Prod [...] 6817139005

its a single rail at 25A is that enough do you think?

I have friends with Corsair PSUs that run flawlessly, so I would assume if there is something wrong with yours, its just a bad one that made it out of the factory, RMA it and you should be good.

Remember no company is perfect......

52 amps made me think that also.

And you are only using 1 rail for the card?

I dont really know much about power units, it only has one rail so i guess yes? This one doesn't have connecter for the GPU so I have a converter going into two sockets. The corsair is plugged in directly, the card has one socket

Two culprits:

1. PSU
2. Motherboard

Speedfan has never reported the correct 12v readings for me, EVER....I even updated just now from 4.33 to 4.37 and no change, still off

Everest However seems much more accurate.

Here the statistics after running riva tuner for a while at the same time as furmark

I've tested the system on another motherboard and its exactly the same. I'm beginning to think that this is just a dodgy graphics card.

Have you tried another card in place of the 8800GT? I think that should help narrow it down as well.

its now completely died., im getting a garbled screen at boot