I’m using glReadPixels in my app, and one thing is bugging me: on NV hardware GF4 4400, GFFX 5800 ultra glReadPixels is able to read at 170 MB/s, on ATI hardware with latest drivers, AGP8x enabled, the best case ist only 75 MB/s. Anyone achieved better results?
No idea. The first time I heard of this issue was in mid-summer, I think. You could always toss a message to ATI developer relations and inquire as to the state of the issue.
Someone could put here a simple test application (so that all tests would be exactly same). It would be niec to have some good statistics about this kind of stuff.
And I am really curious… what would you all consider a good value?
Originally posted by OldMan:
[b]Someone could put here a simple test application (so that all tests would be exactly same). It would be niec to have some good statistics about this kind of stuff.
And I am really curious… what would you all consider a good value?[/b]
Have a look at this thread . It has a link to a small benchmark and lots of performance data
since Lev was asking about a low reading speed on ATI cards, I cannot see how the nVidia pixel data range extension is helpful.
The last time I asked ATI about the reading speed issue (along with a small test application to show them the difference between ATI and NVidia cards), the answer was:
"our QA has reproduced this problem and filed the bug with the driver guys.
Not sure if they will be able to make a difference, but thanks for the benchmark program!"
Originally posted by Elixer: hmm… I can’t access that file your talking about… perhaps it has to do with the date of the original post and the file is now gone?