Strange results with RivaTuner and eVGA 6600GT

[Fardringle]

I just upgraded my computer to a new eVGA 6600GT video card. I don't do any intensive gaming so I don't need anything particularly powerful, but it was time to finally dump the old MX440.

Anyway, the card runs quite well for what I do at stock speeds and I don't really NEED to overclock it, but when did that ever stop anyone? This is a completely new install of Windows XP with SP2 and all updates installed. I installed RivaTuner this morning and attempted to do some minor overclocking. Stock speeds for this card are 500MHz core and 900MHz memory. The automatic detect feature said that the card should be able to handle close to 600MHz core and 1200MHz memory. Even if it would actually run at those speeds I doubt it would work. I tried going with 550 core and 1100 memory at first but the "Test" button reported that the drivers failed to initialize. I tried then at 525/1000 and still got the same results. So, I went with 501/901 and the test STILL failed.

I suspect that RivaTuner is just reading something wrong in its test with the drivers I have installed (I'm running 77.72 since some research on the Internet seems to indicate these are the best for the 6600GT) but the program won't even let me save any overclocked settings without completing the initial test first so I can't try any stress testing in 3DMark or rthdribl.

Another thing that concerns me is that with RivaTuner installed (not even overclocked) I get frequent "flashes" across the screen that look like the card is failing to render one or two consecutive frames in a row while playing games. They aren't normal blocky or streaked artifacts, it's more like the effect of someone waving a sheet of paper or a wooden board or something quickly in front of a TV, obscuring the picture for a fraction of a second. As soon as I uninstalled RivaTuner and restarted the PC, games returned to normal again.

I have not tried any other versions of the ForceWare drivers yet as I really haven't had the time (or desire) to do so. I'll probably do just that in the morning unless you folks have a better suggestion.

Is it possible that RivaTuner just isn't compatible with my video card, or with the driver version I'm using?

 

[mwmorph]

some bioses lock down the clocks. I remember ati used to do this and you had to get a 3rd party bbios that allowed overclocking on 9500s i think.

btw, i recommend you just use coolbits 2. It's actually driver integrated and fully compatible and uses almost no memory footprint(rivatuner uses a few MB, coolbits uses a few KB).

 

[Fardringle]

Yeah, I've used Coolbits in the past. I just wanted to try RivaTuner since it actually has a temperature monitor included (which does actually work on my card, although the overclocking doesn't). I'll try Coolbits in the morning to see what happens.

 

[Fardringle]

I've been playing with CoolBits 2 for a couple of days and it looks like it's having better results at actually getting an overclock out of my video card that RivaTuner did. Strangely enough it appears that this card is a mediocre overclocker at best. This isn't really a big deal for me since I don't play any games that stress it out even at stock speeds, but I like overclocking stuff regardless.

Anyway, my card is running happily at 550 core, 1025 memory (stock is 500/900). It will pass tests including RTHDRIBL at 560/1040 but I get a few artifacts in games at that speed so I'll still with the stable/minor overclock and enjoy the 16800 3DMark score compared to the ~7000 I was getting with my old MX440.