My Seagate Barracuda 80GB ST380021A drive is on it's way out! I am researching a replacement, but do not know what difference the cache makes. My current drive is 7200RPM with 2MB cache, and my Dell can take up to 120GB (according to them - Dell Dimension 4550). Most of the PATA drives I have seen seem to be 8MB. Would be grateful for advice on whether I must stick to 2MB.