Re: Firefox + Flash terribly slow
Flash performance is quite demonstrably not tied to CPU performance alone. I have no doubt that it doesn't (and never did) take advantage of hardware acceleration with Compiz running but the performance of the unaccelerated rendering path it does use is tied closely to Xorg and the display driver.
My Phenom II X3 720 with 64-bit Flash 10 barely gets 10 FPS from a fullscreen low-quality Youtube video. Others have had the same problem only to magically see great performance under some conditions (notably by fiddling with vsync) only for it to revert to poor performance after a reboot.
Flash may be written badly but that alone cannot account for the highly variable performance experienced on the same and different graphics hardware by different people. I cannot attribute the problem directly to one component of the system but it is very relevant discussion to this forum, regardless.