3.5" Western Digital Caviar RE WD1600SD
We picked a set of decent SATA drives to compare to the 2.5" Fujitsu drives. These RAID edition drives are validated for professional applications running 24/7, and thus feature a MTBF of one million hours.
Equipped with 8 MB cache and running at 7,200 RPM, the 3.5" WD drives will obviously be faster than the 2.5" Fujitsus at their slower 5,400 RPM. The seek time provided by WD (8.9 ms) underscores our point about performance. Western Digital's RAID edition is based on a 80 GB per platter design; while this is no longer state of the art, it is likely a tradeoff one must accept for continuous operation.
As mentioned before, the 3.5" WD drives consume four times as much energy as the 2.5" drives by Fujitsu. When running in idle mode, energy consumption of the WD drive is a whopping ten times higher. Also, there is a huge difference in weight: the WD drive has six times the mass of the 2.5" Fujitsu.