View Full Version : Video card overclocking

11-05-03, 07:35 AM
This is sort of a general question about overclocking video cards, it's nothing specifically related to NVIDIA.

I was playing with this 9800NP and I got to thinking about how overclocking can impact various aspects of 3D. The core on this particular card seems to overclock exceptionally well (400, up from stock 325) but the memory doesn't fare as well (320 up from 290). To put it in question form:

What is the specific impact of overclocking the core? Where do you see the most performance increases? Is it in things like fill rate or shader performance? Or does it affect something completely different? Same questions apply for overclocking the memory.

11-05-03, 08:24 AM
core OCing=shaders fasters
memory OCing=faster fill rate

I think....

11-05-03, 09:07 AM
I think that all operations that aren't related to the actual drawing of textures are handled by the core (note that I may be wrong...yes, me being wrong, hard to believe, I know). So for things like shaders and effects, the core will make the biggest difference. But for things like high-res textures, the memory speed will be most important. Basicly, I think of the core as drawing the polygons and shaders and such, and then the memory texturing everything and applying bump-maps and things like that. Actually, now that I think about it the core may also affect the rendering of bump-maps as well, but I'd have to do some testing to be sure. Oh, and I think that because of the way the Radeons use Anti-aliasing, the core speed *might* have a bigger impact with high anti-aliasing then the memory does.

Usually memory speed is more important at higher resolutions, but really you just have to find a balance between the two. If you only raise the memory speed, eventually the core will become the bottleneck and raising the memory speed any more won't make a difference. But if a game uses a lot of transparencies, memory will make the biggest difference. An FX card with 800 mhz memory will beat a 600 mhz memory 9800, because while the 9800 has much better optimisations, it simply can't keep up with the FX's fill-rate. But no matter what the card, overdraw will absolutly kill the framerate, it's just that faster memory kills it slightly less.

11-05-03, 09:15 AM
I see Dave Baumann is lurking right now. Perhaps he can give us some slightly more concrete answers. :cool:

11-05-03, 09:26 AM
Originally posted by saturnotaku
I see Dave Baumann is lurking right now. Perhaps he can give us some slightly more concrete answers. :cool:
"OCing good! Make card go much fastlier.", says Mr. Baumann dumbing it down a bit for a non-B3D site. ;)