[hazeh]

Regarding the optical sound output from the MB... Do they just work or are there any issues with particular models and chipset brands?

They tend to 'just work' - I can't say with 100% certainty, but I think you'd be hard pressed to find an audio chipset on a motherboard that isn't supported by alsa/linux/ubuntu/etc.

[AlmostEvil]

You should go nvidia if you're also going Linux.

However if you're going to be using Windows then there's nothing wrong with going ATI. I personally avoid nvidia ever since I had three of their graphics chipsets die on me. (no joke, two graphic cards in a pc and the 8600M GT chipset in my Macbook Pro)

The dsplayer fork of XBMC is looking pretty damn hot, on windows it uses DXVA to offload h264 decoding to the graphics card. So it's not just limited to Linux now.

Avoid onboard graphics.

I'd been previously using XBMC with my motherboards onboard graphics (HD3200) outputting at 720p with my small portable tv however I recently bought a nice big 1080p tv and set its resolution to 1920x1080 and all of a sudden I was getting dropped frames. Turns out it must have a real bandwidth issue, I'm not sure how it works but I suspect since the onboard chipset uses the motherboard memory it was having to copy the data back and forth multiple times to the same memory and essentially hit a memory bandwidth limit, as a test I overclocked the fsb slightly and noticed an improvement in reduced dropped frames.

However, I decided instead to just buy a cheap passively cooled low profile HD4350 and without anything oc'ed it isn't dropping frames any more.

The CPU I use is a AMD 5050e and there isn't a single 1080p video that it has choked on yet. (smooth as silk)

EDIT: Can't believe I missed the mention of Linux in the op, I blame lack of sleep.

[Milleman]

I'm planning to purchase the newly released Video card from Zotac, the Zotac GeForce GT 220 ZONE Edition Fanless Video Card. Looks like it would be ideal for XBMC and video playback. Anyone here who have tried that one yet?

[hazeh]

I just bought a gt220 for VDPAU feature set C. Looks like a great card for linux video with the binary blob.

I havn't built my machine yet, but I'm under the impression that hdmi audio is not working yet in linux - If you're ok playing the waiting game (assuming it'll come) for nvidia/alsa drivers or do not need hdmi audio, I think it'll be a great card.

edit: I think I read somewhere that the ion2 platform will feature the same gfx chipset, that and the fact that this card is aimed (surely?) at the htpc market, I would be surprised if audio support is not on it's way.

[Milleman]

....
edit: I think I read somewhere that the ion2 platform will feature the same gfx chipset, that and the fact that this card is aimed (surely?) at the htpc market, I would be surprised if audio support is not on it's way.

Oh wow! That sounds like a great combination. Are there any release date yet for the ION2 platform?

For the sound part, I'm gonna use the optical port om the MB. If it one day works with the HDMI audio, that's just a bonus then.