Overclock = lower performance????

Nirad9er

2[H]4U
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Feb 18, 2004
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ok I ran 3dmark06 at stock speed 650/1600 on my pny 7900gtx and got just above 6200 then I overclocked to 690/1760 and I only got 5882.

3dmark05 went from 11200 at stock to 10100

What the heck is going on here? How could a overclock result in lower performance. When I run 3dmark everything looks perfectly stable with no artifacts.

My load temps never get past 66 degrees so heat shouldn't be an issue

Any one know what would cause this?
 
Pull the memory back to 1730 at max to match the 690 core. You should see a bump.
 
I see the same scenario happening on my 7800gt. I reduced my speeds to what (logically) made sense, an equal ratio to my core speed, and gained a full 400 3dM05 points (which had decreased by 280 following my most recent overclock). Do what the suggestion above details.
 
Arcygenical said:
I see the same scenario happening on my 7800gt. I reduced my speeds to what (logically) made sense, an equal ratio to my core speed, and gained a full 400 3dM05 points (which had decreased by 280 following my most recent overclock). Do what the suggestion above details.
what's your OC ?
 
Yep..it's just like CPU's, they will reach a maximum speed (with errors) and work better at slightly lower speeds as to not rely on ECC to correct the data.
 
The reason for the lower performance is because the card can't handle that speed.

nvidia drivers can dinamically underclock to avoid crash, that's why performance is lower with a high overclock even if it seems "stable".
 
ok, so i went back to the 84.21 official drivers and I got 6540 in 3dmark06. Everything seems good now.

I still have one problem though. While running at that clock speed of 690/1760, when I go to play fear, after about ten minutes of playing, the game will lock up for about 10-15 seconds , and then resume playing like it recovered from something. Everything seems stable and there are no artifacts and load temps at max are 66 degrees.

All my other games seem to run fine. I played battlefield 2 for a good few hours at that clock speed and everything ran fine.

Any reason for the cause of this? I went from x1800xt to this 7900gtx. Should I maybe do a reformat of windows to make sure everything was cleaned out?
 
Nirad9er said:
ok, so i went back to the 84.21 official drivers and I got 6540 in 3dmark06. Everything seems good now.

I still have one problem though. While running at that clock speed of 690/1760, when I go to play fear, after about ten minutes of playing, the game will lock up for about 10-15 seconds , and then resume playing like it recovered from something. Everything seems stable and there are no artifacts and load temps at max are 66 degrees.

All my other games seem to run fine. I played battlefield 2 for a good few hours at that clock speed and everything ran fine.

Any reason for the cause of this? I went from x1800xt to this 7900gtx. Should I maybe do a reformat of windows to make sure everything was cleaned out?

Its for the same reason I explained above, nvidia drivers can recover from a "crash", that's why you see pauses on some games. Games like FEAR and Doom3 and benchmarks like 3dmark 05 and 06 are more susceptible to overclocking. For example, I can run FEAR with my 6800GT @ 400/1.16 with no problems but 3dmark 05 will pause for a few seconds mainly on proxycon.

Lowering your clockspeeds by 10~20mhz should get rid of the pauses.
 
Stoly said:
Its for the same reason I explained above, nvidia drivers can recover from a "crash", that's why you see pauses on some games. Games like FEAR and Doom3 and benchmarks like 3dmark 05 and 06 are more susceptible to overclocking. For example, I can run FEAR with my 6800GT @ 400/1.16 with no problems but 3dmark 05 will pause for a few seconds mainly on proxycon.

Lowering your clockspeeds by 10~20mhz should get rid of the pauses.

Yeah, I can run 3dmark05/06 all day long and it would never lockup/freeze at the clockspeed. Its just funny how when I start playing fear and it run awesome and looks great and no artifacts whatsoever...looks perfrectly stable and then out of the blue, the fear will freeze for like 20 seconds at the most, then recover and runs like crap after.

Do you think a driver update would fix this instability cause everything else runs fine, no lock ups or anything?

Would Raising the pci -express frequency fix things?
 
Eastcoasthandle said:
Does this help anyone?
link

Anand had showed similar stepped scaling:
http://www.anandtech.com/video/showdoc.aspx?i=2479&p=3
http://www.anandtech.com/video/showdoc.aspx?i=2487&p=3
http://www.anandtech.com/video/showdoc.aspx?i=2494&p=3

So I presume its the same for the 7900GTX? does the Geometric clock thing in the BIOS do anything?

so for a 7900GTX, good clocks would be:
24x27 = 648
25x27 = 675
26x27 = 702

or maybe we should add 27Mhz to the stock...
650 + 27 = 677
677 + 27 = 704
etc..

I'm going to try 675 & 677 this weekend and see whats the difference.
 
So is that saying if I reduce core from 690 to 677 that it would be the same performance because the next big boost would be 704? Plus I would get better stability anyway right. Cause I keep getting a lockup/recover in Fear, but yet I have no artifacts and all my other games including bf2 run perfect at 690/1760

What about the memory? Should I try 1735 instead of 1760 cause the stepup would be 1762?
 
Nirad9er said:
So is that saying if I reduce core from 690 to 677 that it would be the same performance because the next big boost would be 704? Plus I would get better stability anyway right. Cause I keep getting a lockup/recover in Fear, but yet I have no artifacts and all my other games including bf2 run perfect at 690/1760

Yep, try both 677 & 690, and see. You should have very similar performance but much lower temps & better stability.
 
I also have my 7900gtx overclocked to 690/880. The only game/app that messes up for me is Farcry. Game doesn't mess up in the game except one time in single player when I think the problem may have been stuff running in the background. The game messes up everytime when I got to multiplayer and bring up the list of servers, within a couple seconds or so, the game just freezes and I get a blue screen and restart. Does this have anything to do with the video card overclock or is this some other software/driver problem. I either get a blue screen with "beginning to dump physical memory" or someething about nv4_disp.dll. Not sure how to fix it, tried almost everything I can think of.
 
Anyone try this to see if there is a plateau around 27Mhz at a time?

I was too lazy this weekend to try.
 
Dutt1113 said:
I also have my 7900gtx overclocked to 690/880. The only game/app that messes up for me is Farcry. Game doesn't mess up in the game except one time in single player when I think the problem may have been stuff running in the background. The game messes up everytime when I got to multiplayer and bring up the list of servers, within a couple seconds or so, the game just freezes and I get a blue screen and restart. Does this have anything to do with the video card overclock or is this some other software/driver problem. I either get a blue screen with "beginning to dump physical memory" or someething about nv4_disp.dll. Not sure how to fix it, tried almost everything I can think of.

Try running it at stock and see if that fixes it. If so that means you're pushing the overclock too far. DUH! :)
 
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