SCSI vs. IDE: Size Counts, and So Do ApplicationsYou might have noticed that you can't get SCSI drives as big as IDE drives. Have you ever wondered why that is? While you can get very large SCSI drives, the commonly available SCSI drives generally max out well below the IDE drives used on many desktop systems. The reason is the different way the drives are used. Generally, users who buy SCSI drives are, as a rule, more interested in performance than price. After all, SCSI drives, controllers, and such are significantly more expensive than IDE components simply because they cost more to manufacture. If you are using multiple drives in arrays, such as RAID arrays, bigger is not necessarily better. If high performance is your goal; you're almost always better off with more drives ("spindles" in the vernacular) than bigger drives. The reason is that you can improve performance in most cases by striping, or writing, the data across more than one drive so parts of the file can be read or written simultaneously by different drives. The array controller takes care of the job of parceling out the data and reassembling it before sending it back to the computer. As a result, SCSI customers prefer smaller drives compared to IDE customers. IDE drive buyers are traditionally trying to get the most capacity they can for their dollar. Keep in mind that there are other important differences between IDE and SCSI drives. SCSI drives tend to turn faster, up to 15,000 RPM, for faster data access. Also, SCSI drives tend to be of higher quality than IDE drives. Once again, it's a matter of understanding your needs before you decide what kind of drive to buy.
| 
Acronis Inc. Backup software.