A mainstream 7,200 RPM ATA or Serial ATA hard drive is the best option for almost any system. Such drives are fast, cheap, and reliable. The best models are quiet and generate less heat. While designing your system, use one of these drives unless you have no other plans. Go for a 15,000 RPM SCSI drive if you want the highest possible disk performance and if don’t mind paying few extra bugs. Avoid 5,400 RPM ATA drives, costing a few little dollars less than 7,200 RPM models but have poor performance.