Disk space Vs performance

Although there are exceptions, in very general terms the higher the capacity the better the performance. This is because for a fixed speed (most laptop drives spin at 5400rpm) a higher capacity drive will have more data packed into each track, and therefore you'll be able to read or write more data with each turn of the disk. It also means that a given amount of data won't use up as many tracks, and that leads to less head movement, which is a good thing.

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