Just ran through the auto-tune for ATI Overdrive on my HD 5870 and the GPU won't go above 400mhz anymore, even though I have it set at 900. Prior to touching this, it was sitting at 800m. When going through the auto tune, I had a process showing me the current GPU/Memory, and it went to 900 without issue. After the ... 20 minutes or so for the test, it came back and set the GPU to 400 and the memory to 1290. I don't understand why it's stuck on 400 now ...
I then tried clicking "test custom clocks" and saw my monitor go right back to 900mhz. It came back good, yet still on 400. I'm very much so new to the whole oc'ing world, so perhaps I'm simply over looking something.
It's not a problem, it's simply a power-saving thing that ATI has in all of their drivers. What you are looking at when it's at 400 is the 2d clock speeds. What you have set at 900 are the 3d clock speeds. ATI drivers detect when you are using a 3d application, and boost the clock speeds accordingly. When you are in 2d mode, it significantly lowers them in order to save power.
To see for yourself, try a program like GPU-Z, set it to update when it's in the background, and have it start logging your clock speed. Then, run a 3d game. After you've played for a while, exit out and check the log. You'll find that as soon as you started the game, your speeds jumped right up to the 900MHz you set it at.
Congrats on the 5870 by the way, it's an excellent card isn't it?
Thanks Duck, I just literally 2 seconds ago found a thread stating something similar. So I launched Starcraft 2 and yep ... went right back to 900, phew.
Honestly, I'm having some buyers remorse. I bought the ASUS Crosshair IV, Phenom 1090t, and this video card. I mean, the system runs like a CHAMP, but I keep reading more and more into the whole performance/oc world, and it seems like nVidia is the better performer of the two these days. So I feel like I may have made a bad decision ... did I? Seems like it might have been better to pony up a couple hundred more dollars and get that 480 card or whatever it is that seems to be the #1 in benchmarks ... same goes for the i7 vs 1090.
For me it was, but I had somewhat of an unlimited budget. Don't spend the extra money if you really can't afford it. For the money you DID spend, however, the 5870 is the absolute best you can get. That card SCREAMS value. You made a good choice, don't fret over it.