I installed a Gigabyte 670 today and it seems pretty great, at least most of the time.
After playing around with clocks a bit I went into BF3 to test it out, and everything ran as it should, but trouble began when playing WoW. I got a black screen that lasted maybe 4-5 seconds, as if the display driver had stopped working, and then the core reset to stock, un-boosted clock (980 MHz) and memory clocks dropped all the way down to 162 MHz! After a few minutes memory clock went back up, but I had to restart Precision X to re-apply core clock (which I guess is normal).
I'd only applied a very modest 35 MHz OC to the core and none to the memory as it's my first nVidia card so wanted to start out slow; according to GPU-Z the GPU never went above 73% of the TDP and temps were hitting low 50s. I checked the GPU-Z log file and noticed the voltage (which, when under load, always runs as 1.175) had dropped down to 0.9xx mv at the same time the clocks went haywire. I'm wondering whether my PSU is being run to its limit (it only has 408W on the 12v rail) or if it's WoW that's being weird (it didn't happen in BF3).
I've only got a single HDD, a 2500k at 4.2 GHz and 3 fans running so I'd be surprised if the PSU is actually running at full capacity.
I read this guide: http://www.overclock.net/t/1265110/the-gtx-670-overcloc...
and noticed my "Kepler Boost" seems to vary from 52 to 13, depending on the clock offset. The boost clock is 1058 at stock and the card runs at 1110 under load (+52 Mhz) but if I OC the core, the Kepler Boost simply doesn't 'boost' as much, despite temps still being in the 50s.
I'm really at a loss here and wondering whether I should get a more capable PSU, return the card or admit defeat and run it at stock (which is really a very boring way of using an expensive graphics card).
Yes, a 500W PSU - there's no specification of how many watts are needed on the 12V rail.
Also, I had a 7950 installed up until today that I decided to return; it displayed none of the same issues. It was clocked at 1000/1250 rather than the 1110/1500 my 670 runs at, so it doesn't rule out the PSU, but neither does it confirm it as the issue.
It's an Arctic Cooling, although this particular model is made by Seasonic (according to the AnandTech review I read of it ages ago). Upgrading the PSU would be an easy fix, and I dont mind spending $100 on one - so long as it proves definitively to be the problem.
So boring though! A GPU is not a tool, it's a toy, albeit an expensive one. Reading about 1300 core clocks makes me want to achieve something similar.
If I have to run it at 1110 core (which is the boosted "stock" clock") then so be it, as long as it's stable - part of the reason behind this post was also the instability I experienced.
Dude, you are cooking your computer. Get a new power supply at greater rating. Overclocking processors and graphics cards takes lots of power. Get a quality 650 or even 750 and you don't have to worry. If you want to play, you've got to pay. Having a power supply brown out like that is very dangerous. You can blow out parts of your computer.
750 is definitely way more than I'll ever need. Multi-gpu setups aren't my thing, so 650 is probably the way to go. I do suspect my current PSU is making noises when at load, which is quite annoying. I can't be sure, as it's somewhat of a challenge isolating one fan noise over half a dozen other ones in a cramped case. Of course I'll have to wait until monday with ordering, duh.
Edit: I want to make sure I interpret the specs properly. Will this PSU fit in any ATX case, or are there differing sizes? It says "ATX v2.31" and my current one is 2.2, whatever that means. My mobo uses a 4pin and a 24pin, I assume >1 x Main connector (20+4Pin) and 1 x 4+4 Pin CPU< means it's compatible?