Don't be so quick to blame the amount of memory on your video card for slow speed. Standard 2D graphics uses very little memory.
For example, 800wx600hx24b = 1.44MB. Even triple buffered, that's only 4.32 MB. Anything above that is unused in 2D. Unless you're running in 3D, you're just not using that much memory.
Start with basics. Check your task manager and see if any process is hogging the CPU. Are you running any flash animated icons, etc? Any background processes?
That Via CPU isn't exactly that fast either. I'd be looking there first if you're worried about your CPU load.