Hard Drive Size
The PS3 uses a 2.5 SATA hard drive, the same size used in many laptop computers. RPMs can vary between 5,400 and 7,200, which are both acceptable.
Gigabytes
The hard drive has a variety of upgradeable gigabyte sizes, which is directly relative to the amount of space that you have for storage. As of 2010, the maximum gigabyte size available for a 2.5 SATA drive is 750 GB. A variety of smaller sizes also are available, such as 250, 500 and 640GB.
Brand
Most hard drive brands will function properly inside the PS3. Brands like Seagate, Western Digital and Samsung are compatible with the PS3. Using an off-brand could be a gamble. If you install an incompatible hard drive, you take the risk of potentially losing valuable information.