GTX 260 SC Edition overclock?

[jerkinjohn]

Does any one know why after overclocking my GPU to 740/1485/1200 fan 80% my 3DMark benchmark went from 19694 at stock clock to 14405 after the overclock? Doesn't make any sense to me! Ran OCCT with no errors. http://www.techpowerup.com/gpuz/w9y8b/



Cooler Master HAF 932
Intel Quad Core Q6600 OC@ 3.0 Ghz
Noctua NH-D14 HS
Evga 750I FTW Mobo
Evga GTX260 Super Overclocked Edition GPU
Corsair TX750W PSU
G.SKILL 4GB (2 x 2GB) DDR2 1066 (PC2 8500)
Western Digital Caviar Black SATA 3.0Gb/s 1TB 7200 RPM
ASUS DVD Burner DRW-22B1LT
Hanns·G HG-281DPB 1920 x 1200
Windows XP Professional SP3 32-bit for System Builders

 

[jerkinjohn]

Well I figured out what was going on I think. When I would attempt my overclock and it would fail it would just downclock and stay at that downclock unless I rebooted. So if I ran 3DMark with the (locked) downclock my benchmark score would dramatically drop! If i reset precision and rebooted then I would be back at stock clock and my benchmark score would be much better. I have been trying and trying to overclock and using Ati I show no errors and have no problem running 3DMark but then as soon as I start OCCT I show a whole boat load of errors unless I'm at stock clock.

I have been raising shader/memory/core 10 Mhz at a time but so far can't seem to get this thing to overclock without errors with OCCT. I have the latest display driver and version of precision. I'm going to try Evga's OC Scanner to see if that makes any difference.

 

[OvrClkr]

Open up CPU-Z and check to see if you have the 55nm or 65nm version. I had the 55nm version and was able to OC the card pretty far by raising the voltage, example :

http://i683.photobucket.com/albums/vv199/OvrClkr/newburner.png

More info on voltage control :
http://www.techpowerup.com/82842/EVGA_Prepares_Software-Control_For_GPU_Voltages.html