>I need to buy an internal hard disk for server at home. I am looking for something between 300 and 500 GB and am most concerned with performance since prices are relatively close. A larger disk will consume memory to hold the equivalent of the FAT map, right? The server currently has 1.25 GB memory and can go up to 2GB. How big a chunk of memory will a 500 GB disk require?

RAM usage to mount additional volumes is not large enough to worry about. If you're still concerned, spend an extra $50 to buy an extra 512MB RAM strip.

Commodity 7,200rpm drives are very similar in specs and performance. Larger sizes these days are typically available only with Serial ATA interface, if your machine doesn't have an SATA controller you'll need to buy one. One thing worth looking at is warranty period - at the moment Seagate is offering a 320GB unit with a 5 year warranty for just C$125.

If you're interested in performance details you can take a look at sites such as Tom's Hardware ( www.tomshardware.com ) or AnandTech ( www.anandtech.com ).

For single drives, you can get higher performance if you buy a 10,000rpm drive such as the Western Digital Raptor series. These are significantly more expensive, however.

For ultimate performance in standard form factors SCSI is the way to go; drives are typically 10,000rpm and some are even 15,000rpm.

There are various techniques you can use to combine multiple drives to get higher performance and reliability (e.g. RAID). You can check out the above-mentioned sites which have good overviews and real-world performance measures.