Just to make one thing clear.... my X2-4800 is on a socket 939, so just plain old DDR (not even DDR2). The memory speed won't have any significant impact on video decoding since you're dealing with a stream that is nice and predictable and far far lower than what the memory can handle.
I know what you mean, although, i had a much slower cpu than the athlon 64x2 4800... Anyways, the ddr systems tend to have a lot more problems with 1920x1080 streams then 1280x720 streams.
Originally Posted by droidhacker
The two systems have enough power to handle the highest levels of hd content. The main suggestion i have is keep the system on the fglrx driver, and if you should reinstall, use the onboard card until you get the closed source driver installed before trying the hd5000 series. Also, the Athlon II x2 should handle any video with software decoding, also see my previous post about installing the xbmc subversion release.
Originally Posted by acreda
Make sure that you're using a MULTI-THREADED video decoder.
HD5xxx (Evergreen) and X
The issue right now (with Penguinista Catalysta, AKA closed-source AMD Linux drivers) is more X than kernel-related (specifically, X 1.9); however, that version of X is only in test/development versions of Linux (no shipping/normal-use *desktop* distribution is using it). The kernel issue is more that some distributions never moved away from 2.6.32 (notably Fedora); if you are okay with moving to a 2.6.35 kernel (which is an option even for Fedora) you can use the closed-source 10.6 through 10.8s, which support HD5xxx from end to end (including several HTPC-style GPUs, such as HD54xx/HD55xx).
Originally Posted by Dandel
Yes; when openSuSE 11.3 shipped, you needed a patch to run Catalyst 10.7s - however, this was fixed in an update for openSuSE 11.3 (further, 10.8 does not have that issue). Canonical, as usual, has a custom Catalyst for 'buntu (which I use with my HD5450 without issues).
As long as you don't go bleeding-edge with X, and go with a relatively-modern kernel, you're fine with HD5xxx and closed-source.