GTX 275 overclock help

[ChrisLandin]

Hiya.
Can anyone please post some good ideas as where to start overclocking my xfx gtx 275 cards please? Im looking to get the best performance possible with these cards.

Thanks

 

[elpedro]

Download EVGA Precision - http://downloads.guru3d.com/EVGA-Precision-1.7.1-download-2251.html

Look at the speeds of the top end OC models and use their speeds as a base to start from, then start increasing core, shader and memory clock.

BFG - http://www.overclockers.co.uk/showproduct.php?prodid=gx-089-bg
core: 709mhz
shader: 1566mhz
memory: 1242mhz

test stability with something like furmark - http://downloads.guru3d.com/furmark-v1.7.0-download-2321.html

 

[ChrisLandin]

Elpedro, if i overclock the cards will I have to do both of them as they are in sli? I have run furmark at stock and got an average of 82 fps and 4889 marks, is this decent?

 

[boldenc]

Elpedro, if i overclock the cards will I have to do both of them as they are in sli? I have run furmark at stock and got an average of 82 fps and 4889 marks, is this decent?

4889 marks on what resolution?

 

[ChrisLandin]

1600 x 900 set to custom

 

[elpedro]

Elpedro, if i overclock the cards will I have to do both of them as they are in sli? I have run furmark at stock and got an average of 82 fps and 4889 marks, is this decent?

Yep, SLi will set both cards to the slower clocked of the two, so set them the same.

 

[ChrisLandin]

so i got 5889 marks with the 2 cards in sli with a 1600 x 900 resolution, is this good bad or indifferent?

 

[ChrisLandin]

make that 4889 marks on furmark

 

[elpedro]

Use the stability function not benchmark on Furmark as that's its primary use, for benchmarks use 3D Mark Vantage or you can compare individual game benchmark scores.

 

[ChrisLandin]

when running the stability function what should I be looking for please? When I started to change the clock speed of the cards to like the higher clocked BFG I started to get little black marks on the screen like the size of a grain of rice!! So i have gone back to stock for now, any advice there Elpedro?

 

[elpedro]

You're looking for irregularities appearing on screen, you can also monitor the temperature which at what point these 'artefacts' appear, adjusting fan speed accordingly.