6870 stuttering

[girafferider]

Hey there, I need some help with a computer I built a couple weeks ago. Yesterday I started getting constant stuttering in movies and games that my ancient nvidia card used to run with no problems at all, and some sporadic texture flickering. I don't remember doing anything special that might've caused this, haven't oc'd any component yet either. Modern games (bfbc2, crysis) appear to run alright, card goes to 100% and performs as it's expected to, it just seems to relax too much when it's running older stuff.

I've tried five or six driver versions, played with all the settings in Catalyst, tried a different HD and ran a couple of memtest86 passes, and the problem's still there. PSU is 750W, brand new, but I suppose I can't rule it out as the cause. Here are 3dmark vantage results (slightly lower than I expected, but mostly alright) and a gpu-z log, in case they're of some use. Thanks!

 

[girafferider]

No luck.

 

[girafferider]

No idea what powerplay might be, but it's worth a try I guess. What should I do to fix it?

Edit: did some googling and it does indeed appear in the 6870's specs:
AMD PowerPlay™ power management technology

* Dynamic power management with low power idle state
* Ultra-low power state support for multi-GPU configurations
I suppose that's what's causing the clocks to jump all over the place, haven't found how to disable it though. Setting clocks in afterburner didn't help

 

[girafferider]

On it.

 

[girafferider]

Well the stuttering's not gone, but it's much better now. I'll see if the CPU has some similar power saving mode, disable it and report back

 

[girafferider]

PSU is an antec tp-750, should be able to run two cards like mine

 

[girafferider]

I just happened to find this. Is this normal or is Windows trolling me? Don't really think I need 4GB's of slow virtual vram

 

[girafferider]

Okay I did a clean install to remove the dozen drivers I must've tried, followed this trick to set clocks to 1/3 of full power and it's smooth as silk now.
I really like this card now that it's working alright, but I want to try some of what the AMD engineers were having when they wrote up the drivers. Default 10% underscan on the HDMI output and a power saving system that makes the clock jump several times a second? Give me a break.
Thanks a lot for helping, been scratching my head at this for a long time

 

[girafferider]

I made a bunch of custom profiles, 10% power for web browsing and work, 30% for old games and 100% for maya rendering and new games, and it appears that the stuttering's gone. Haven't done much testing yet, I'll write again tonight and tell you if it's working alright

 

[girafferider]

I restarted and for some god-forsaken reason the card started switching between the profiles, and I was back to square one. The only way I've found to tame it is to use a single profile and edit the values in it when I want to change clocks. Annoying as hell, but it works, with the caveat that if the card's under heavy load it likes to jump to full clocks, but it never goes below the value you set. I'd definitely prefer full control, but this gets rid of the stuttering all right, so it'll have to do till they release a halfway decent driver.
Ignoring the misguided software the card's remarkably good, powerful, efficient and silent, but I can't recommend buying a gaming card that doesn't allow easy and precise clock control. And I might be claiming victory too early, I've no idea if it's gonna start doing more antics when I fire it up tomorrow. If I'd known I would've gone for nvidia.