Mine is also a single core Athlon64, one of the more recent low-power AM2 models to be precise. I do have 4GB DDR2-800, but that's more left-over from other PCs. It does do the occaisonal Hyper-V too. I'm quite like Andy, though I don't backup all of BA, I do have almost the entire OS collection, and a few other things too - totalling just short of 1TB. Then there's TV Shows/Movies, which add up to about 725Gb. And then the more general software collection too. Hence the large space. It does function as the centralised storage for pretty much all the data in my house though.

EDIT (a month later): Verizon uses FTTP