I have a Dell Poweredge 1800 server (dual 2.8GHz 800MHz FSB HT Xeon, 1.5GB RAM).

Before people start telling me I don't need a server for multimedia, I am well aware of this, I use it to run VMWare GSX, which runs my domain and Media Center PCs/Servers, along with other business apps.

That said, I would like to utilise the 2 physical (plus 2 virtual) CPUs to encode videos a bit quicker!

I believe I will need a dedicated VGA and sound card for this (whenever I try to encode using Windows Media Encoder or CuCuSoft AVI->VCD, I get errors saying that I do not have the right codec installed (even though I have installed all codecs under the sun). Oddly, Videora Xbox 360 Video Convertor works, but I think this transcodes rather than converts (is there a difference?).

According to Dell, I have the following expansion slots available -

Six total: two PCI Express slots (1 x 8 lane and 1 x 4 lane);
two PCI-X® slots (64-bit/100MHz); one PCI (32-bit/33MHz, 5v)
and one PCI (64-bit/66MHz).

Now, I can obviously get a PCI graphics card and stick that in the PCI (32-Bit) slot, but can I put a sound card in the 64-Bit slot (or even one of the PCI-X ones? - I seem to recall my M-Audio Delta 2496 saying it was PCI-X compatible on the box, but I'd rather fiund out it's safe before I risk killing the card by trying it!).

Thanks in advance