Well... To answer the hard drive question of what makes them different.There are several items that effect how a drive will function and perform:1. The spindle or platter speed (faster typically leads to better throughput)2. The type of read/write head used (areal data density, i.e., MB or GB per sq. in.)3. The means by which the read/write heads transverse the data surface4. The size of the platters (wider takes longer to transverse, but also can potentially store more data; i.e., 5.25" vs. 2.5")5. The standard for the data connection to the system (i.e., SCSI, IDE/(P)ATA, SATA, MFM, RLL, etc.)6. The bus that's used (8bit, 16bit, 32bit, etc.)There are three main types of drives, or drive connections, in use today ranked in throughput from lowest to highest are: IDE/(P)ATA, SATA, and SCSIIDE/(P)ATA (or simply IDE) has the lowest rank simply because in theory it's maximum peak data transfer rate is 133MB/s for U133 (U as in "Ultra DMA") on a good day with ideal conditions. The IDE U133 is the end of the line (afaik) as the shift has been made to SATA. IDE is a parrellel architechure.SATA currently has a tranfer rate of 150MB/s. It is a relatively new technology with plenty of room to grow in throughput. SATA is a serial architechure.SCSI has a number of formats with the fastest transfer rate being 320MB/s (other rates as I recall are 10MB/s, 20MB/s, 40MB/s, 80MB/s, and 160MB/s. SCSI is a parallel architechure.Most common spindle speeds (in RPM) today are 4200, 4900, 5400, and 7200 for laptops drives and 5400, 7200, 10000/10k, 15000/15k and higher for larger format drives. 7200 is about standard (and max) for most IDE. 7200 and 10000/10k (and possibly higher) are used with SATA. Modern SCSI drives typically start at 7200 and go up from there.You know, I was going to give a big old speal, but instead I found this hdd linky
which I'm sure is more complete and accurate than I ever could be.SCSI drives are all around faster at getting to data. A SCSI drive might have a 5.4ms seek time while an IDE drive might have a 8.9 ms seek time. Hands down, SCSI will get to the data first any day of the week.