In a notebook the harddisk is one of the biggest bottlenecks, simply because most models have only a single platter of fairly low platter density, and their spindle speed is relatively low at around 4200-rpm. For comparison most desktop harddisks have multiple platters and spin at either 5400 or 7200-rpm. This results in most notebook harddisks performing worse than even the slowest desktop drive. One thing does help though, the higher capacity the drive the larger the platter density will need to be and combined with the 4200-rpm spindle speed, these harddisks offer better performance than the lower capacity models. This is simply due to the fact that more bits will be read off of the platter’s surface per platter revolution than with a lower platter density.
Fig 4. IBM Travelstar 32GH mounted in the notebook harddisk bay, as featured on most notebooks.
If you want to upgrade your notebook’s harddisk there’s unfortunately not much to choose from. There are only a handful of manufacturers and most of their products offer similar specifications as competing products. But there’s one exception though, the same company that manufacturers some of the highest performing desktop harddisks, IBM, has a card up their sleeve for the notebook market. They are the only one offering a 2.5” notebook harddisk with a 5400-rpm spindle speed, with either a 32 or 48GB capacity. Naturally these are the very same drives that can be found in the high-end notebook segment as these drives offer the best notebook harddisk performance to date. The models I’m referring to are the IBM Travelstar 32GH and 48GH, both can be ordered at most large retailers, but I’ll warn you beforehand, these top-of-the-line drives don’t come cheap.
Alternatives are the other harddisks in IBM’s line of Travelstar drives, which feature 4200-rpm spindle speeds, and those manufactured by others, such as Toshiba and Hitachi. We’re more or less focusing on IBM and Toshiba here because their drives are easy to come by and can be ordered from most retailers on- and offline unlike most other brands. In case of Toshiba we’d suggest going with their MK3017GAP, 30GB capacity or MK4018GAP, 40GB capacity drive as these offer high platter density and a good price/performance ratio. In terms of performance the IBM and Toshiba 4200-rpm drives are in the same league and we couldn’t really distinguish between them, unlike with IBM’s 5400-rpm models.
More information about IBM's notebook harddisks can be found here: IBM harddisks
More information about Toshiba's notebook harddisks can be found here: Toshiba harddisks