Question on oc'n

[OnDborder]

Ok, I got around to testing the overclock on my 285gtx sli's.
It's been awhile since I've done nvidia.
The last time was with a 8800gtx,, way back when.

The situation is that when running up the clock on mem and gpu, it seems that it would reach a threshold then drop.
For example:testing on 3dm2k5. The gpu 648 would be 24977.
Then gpu 657- 21957.
Gpu 663-24947.
Gpu 670- 20614

My benching on my 8800 did this also.
Does anyone have info or a link to info on this?

[OnDborder]

It's called "straps". GPU, memory, and shader strap.
I had to dig up my old notes..

[jason4207]

Did you clock the shader separately, or did you leave the clocks linked?

[OnDborder]

linked

[dejo]

the thing with straps is that they only move on given icrements. and as far as scores go, once you get past decent stability on the card your scores will often go down, same thing for your cpu. if you go too far you normally dont score as well, other times they just lock up or reboot.

[OnDborder]

Ya, I don't remember having the scores being so varied by bumping it up just a few mhz.
This is all with stock system, no oc on the cpu/mem.

[OnDborder]

2 mhz difference

http://img691.imageshack.us/img691/103/648ae.jpg (http://img691.imageshack.us/i/648ae.jpg/)
http://img94.imageshack.us/img94/8325/650a.jpg (http://img94.imageshack.us/i/650a.jpg/)

[jason4207]

Look at the sensors tab to see more accurate clocks.

Unlink the core and shaders to maximize your OC on each and get the best performance.

What are you using to OC?

[OnDborder]

msi afterburner
I'm going to use another benchmark tomorrow.
It could be 2k5.

[jason4207]

Try using eVGA Precision. With it you can see the the actual clocks running in real-time in the monitor window. What you set is not always what you get when it comes to the sliders.

Did you try looking at the sensor tab in GPU-Z as well? It will also show actual clocks.