Quote Originally Posted by Sampsa View Post
Hi,

Ok here is a short explanation:

First of all, I'm using Race Driver: GRID demo and 4870 CrossFire and 9800 GX2 seem to work just FINE. With 1920x1200 resolution, 4xAA and 16xAF I get 66,9 FPS with single 4870, 73,4 FPS with 4870 CF and 75,6 FPS with 4870 X2:



(Red bar keskimääräinen is average FPS)

Second, the graphs I've showed here related to microstutterin ARE NOT intended to display performance but difference between frame rendering times. I have only recorded 2 seconds of gameplay and used first 30 frames from data.

If performance is 60 FPS.. that would mean graphics card renders 120 frames in 2 seconds. Since I have only used 30 frames to analyze the results and draw the graphs, it means gameplay of half a second (0,5s, 500 ms)!!! That's not enough to draw conclusion about perfromance...

... it might not be enough to draw conclusion about microstuttering either but in my own tests 30 frames already show clear pattern with ATI Radeon HD 3870 X2 and rendering problem where every other frame is being rendered after different time than every other.
Kinda off topic, but any explanation on why your CF / X2 scaling in GRID is so much 'different' than what AnandTech preview shows?

It seems they got close to 100% scaling with X2 compared to single. True the res they used was higher but I don't think this is just a matter of CPU bottlenecking. Your test shows only what, 10% scaling?