There are two main factors you want to look at when performing a notebook hard drive comparison. First you want to look at the storage capacity of the hard drive. The information and data held by a hard drive is measured in gigabytes(GB). For basic computing functions like surfing the web, checking email, and downloading a reasonable amount of files, a notebook hard drive with 60 or 80 GB will be sufficient. Most notebook manufacturers offer hard drives with storage space ranging from 80 GB to 160 GB, with some offering up to 300 GB. There are multimedia and gaming notebooks available that have dual hard drives installed with a total storage capacity of 400-1000 GB. Those computers are often known as "extreme" notebook computers.
The other factor to consider when making a notebook hard drive comparison is the speed of the drives. The faster a drive spins the faster information/data is read and written. The three speeds notebook hard drives usually come in are 4200 RPM, 5400 RPM, and 7200