I just installed a Sapphire HD 5450 video card into my Asus M5A78L-M LE motherboard (which also carries an AMD Athlon II X4 640 CPU). The computer is running Windows XP Home Edition SP3, and I installed Catalyst 13.1 drivers.
In short, 2D performance is stunningly slow. I can actually see it repaint the screen with Firefox, the Windows Start menu, or whatever else I might try. Feels completely unaccelerated.
In contrast, if I dual-boot into Debian Linux (running the non-proprietary radeon DRM driver), 2D performance is VERY fast. Precisely as I would expect.
How can I get graphics under Windows to run equally fast? This is amazingly frustrating.
And note: I pulled out an NVidia 8400GS card to make room for this new Radeon 5450 card. The NVidia behaved flawlessly under Windows, but caused weird audio crackling in my Insignia NS-32L450A11 television (connected via DVI-to-HDMI cable). The Radeon is the other way around. Flawless under Linux. Pitiful under Windows.
Asus M5A78L-M LE Socket AM3+ motherboard (w/BIOS 1302), AMD Athlon II X4 640 CPU @ 3000 MHz, Sapphire Radeon HD 5450 video, 8 gigs PC3-12800 memory, Antec SmartPower 2.0 450W power supply, running Windows XP Home Edition SP3 and Debian Linux 7.0 x86_64.