x850 pro overclock, great mem, poor core.

[TurboGLH]

Hi everyone, just trying to get a little input and maybe get a better o/c out of my card

System
NF7-S Manta Ray D26
1gig hyperx pc3200
koolance pc2 case (I know I know, but it does a great job and it's much more quite than my air setup was)
1800+ (1.53) @ 2.2, 1.75v

x850 pro agp with 16 pipes, got the card last week and after doing some initial bench's went at it. Mem is amazing, ran up to 611 stable/ati tray tool artifact free with no cooling, bumped it back down to 600 for a bit of safety and ran artifact scanner for 24hrs, no problems.

The core on the other hand is not as cooperative, maxing out at 520 on the stock cooler, would hit 68-69c under load, it would go higher but lock up during artifact testing. Revised the fan speed schedule the load temps dropped to 60c and it was stable up to 525.

Being that it's brand new I didn't want to pull the cooler off, but I gave up last night and put it into the water loop. This time I let the auto-overlock give it a shot and was all the way up to 550 when it locked. Tryed setting it a bit lower manually and no luck, ended all the way back down to 532 before it was completely stable. Temps are much better now, 33idle (1-2 lower) but load maxes at 45c (15 degrees lower) but it's not cooperating.

Should I bother with a voltmod at this point? The core is not overclocking very well and I don't want to make those kinds of changes if they won't produce results.

Thanks in advance for any help.

 

[djbbenn]

Take the mem overclock down a bit and see what you get on just the core. Core overclock gives more performance then the mem will. I found I got a high core overclock when I lowered my mem down a bit. The only really good way of getting the core up high, is to vmod. Some cards will overclock better than others out of the box. You may just have a poor overclocker.

-Dan

 

[sniviler]

Strange thing is before I flashed my 850pro the core would do 560/605, now with 16 pipes and the original bios the core only goes to 530/590 before freezing up.

could it be memory timings ?

 

[djbbenn]

Possibly...I think when you unlock pipes too, it uses more power to run the chip. So it can cause a less of a overclock.

-Dan

 

[TurboGLH]

I'm at 540/590 right now, played bf2 for about two hours straight with no problems. I probably helped that I cleaned the rad off, had a layer of cat hair trapped between the fan and the cooler that peeled off. Dropped system temps by 6c. I'll bump it a bit more later and see what happens.