I ordered a new SATA drive without giving much thought on how to arrange & partition it, except that it'll somehow compliment my existing drive. I'd like to leave the original SATA drive as the root OS drive and use the new drive as scratch disk for PS and media storage, if for no other reason than to save reinstalling everything (4 years worth of crap). The new drive arrived today and if someone, anyone could offer advice on the best way to set it up I'd appreciate it. Something hugging the margins of safety and performance would be great ......I'd settle for a point in the right direction- couldn't come up with the right keywords in several search attempts.

Incidentally, this is for XP, 2GB ram, the original drive is 80GB and the new one is 250GB. The motherboard has two different chipsets for raid, the Promise 20378 and the ICH5/ICH5R, as it stand the original drive is in the first ICH5 slot. Thanks!