We're looking to buy a server and many companies suggest we use SAS drives which are expensive and harder to get then SATA drives. If we got good quality enterprise SATA drives like the Western Digital RE3, wouldn't that be just as good and cheeper for that fact? What we're using this for is a network file server so I'm expecting that the speed will be limited to the network and not the hard drive so speed isn't a huge concern. PS - this is not actually a Pentium III, I was trying to not list a computer and it listed the last computer I used. This is just a general server question

Serial Attached Scsi [small computing systems interface] is better than ide on steriods [SATA]. If you are considering RAID, which you should be as you first line in disaster prevention/recovery, SAS is the way to go.

The difference between SATA and SAS is only the controller right? From my knowledge, I always thought that whether a hard drive was better or not depends on the quality of the motors, plates ect. What makes SAS better?

Check and compare the speeds on SAS/SATA as well. SAS drives normally come with higher rpm than SATA is capable of. Higher rpm, faster read/write = better (faster) HDD. When talking about a highend server that's going to see a lot of use and read/write to HDD, then SAS is the way to go. If I had the cash, I'd use SAS (in a RAID) at home!

Fair enough. I understand about speed. Like, for exchange SAS would be the way to go because it's quick. for for a network file server where the speed of the network is the bottle neck, in my mind SATA would work good because its not SATA that is slowing us down. Are SAS drives built with more quality then enterprise SATA drives?

It is the command sets in SCSI that are superior to those of IDE/SATA. SCSI was designed for sustained heavy access where as the ATA standard is not as robust.