I am planning on building a HTPC system, and while I believe my hardware will be sufficient, I am still not totally sure how good it will play-back HD TV and Blu-ray, etc.
My biggest question I suppose is, the more expensive/higher-rated a hardware is (such as a graphics card), will it play movies clearer/faster?
Right now I have a DFI RS482 (mATX) board, with a PC2700 RAM, but it is only 1 GB.
As for a graphics card, I was thinking of the Radeon HD series, but which? Once the HD 3450 comes out, I want that because it's passive cooled, but will it hinder my HD experience as compared to, oh, a HD 3850?
Any other hardware suggestions would be welcome, like a TV Tuner, because I am not too familiar in terms of what's good and bad with those...
While I expect budget based cards like the HD3450 to be able to play HD content, fast moving scenes could be too much for it. I can never really recommend a budget class card. If you're willing to wait for the HD3450, then I would recommend actually getting the HD3650 which should be out around the same time frame.
I'd also recommend doubling your RAM to 2 GB.
You don't mention what type of processor you have installed, but I would recommend a dual-core if you don't have one already. Dual-Core Opterons are still available in a few places.
As far as TV Tuners are concerned, I'd look to either Hauppauge, AVerMedia, or ATI's TV-Pro series with a PCI-Ex1 interface.
What O/S are you considering? Vista Home Pro? MCE 2k5? Something else?
I second the 2 GB minimum. My HTPC (MCE 2k5) eats more than 1 GB all the time. So will Vista, from what I hear.
Is this going to be in a component rack, a Hi Fi cabinet, or deskside? If it's going to be in the L.R. (you are concerned about sound), you'll want to focus on the coolest-running parts you can find. You might be better off with something like an HD2600XT than a higher-powered card, and you might also be better off with a card with a slow, case-exhausting fan than either no fan (increasing load on your case fan - which can be tough with the HTPC form-factor), or an internal fan (same problem).