High Capacity Drives
At this point, the mainstream and sweet spot for 3.5" hard drives still are somewhere between 160 and 200 GB, since 160 GB still is plenty of storage space for your operating system and an average amount of data for average Joe. In addition, the hard drive makers produce 160 GB hard drives with a single platter today, which helps to keep production costs low.
We define over 500 GB as high capacity, even though the first terabyte hard drive doubles this capacity. Only Seagate and Hitachi offer hard drives with over 500 GB of capacity, but it is only a matter of a few months until other hard drive makers will follow with larger capacity drives.
Hitachi Deskstar 7K1000 - 1 TB
Hitachi's Deskstar 7K1000 currently is the world's largest desktop hard drive. Its five platters spin at 7,200 RPM and the drive carries as much as 32 MB cache memory. Hitachi uses a Serial ATA/300 interface with Command Queuing to communicate with the host system. We found that the drive's performance is excellent, although it is not the undisputed performance champion. Other 7,200 RPM drives perform similarly well, and there still is Western Digital's 10,000 RPM Raptor drive, which delivers much quicker access time.
At $450, this drive is extraordinarily expensive, which can be justified by its uniqueness. If you're looking for maximum storage capacity, there is no alternative to the 7K1000.