i just tried it on the htpc. it chops a bit on anaglyph due to the extra processing power needed(90-100% cpu usage in the worst scenes), but monoscopic's fine. Even the 21GB 2d avatar rip works flawlessly, with cpu usage never once going beyond 40%
and the poor little thing has a combined windows performance rating of a mere 3.3! memory being 4.9(well not utterly shitty but every single thing is still much much worse than the gamer rig except for the hdd which is seeing NO usage since i'm streaming) - I guess the HTPC community just isn't ready for x64.
i don't really have any use for x64 so i'll just reinstall with x86 and see what happens. The main reason i installed 64 was for future-proofing(if i upgrade my RAM) and maximum performance. I don't have any x64 programs, so right now i just end up getting worse performance(and, MUCH worse video playback)
EDIT; Sure enough, installed win7 x86 and it plays just about anything without complaining.