7200 rpm vs. 5400 rpm vs. 4200 rpm hardisk

7200 rpm vs. 5400 rpm vs. 4200 rpm

The main thing Tom's hard drive review covered was hard drive performance. The drives covered were all 80 and 100 GB drives, other than the 60GB 7200 RPM Hitachi drive.

Here is a quick table to summarize the Maximum and Minimum throughput, which is generally the biggest advantage that hard drives with faster spindle speeds (RPM) have. Throughput and access time (an average of how fast the hard drive can find data) are the primary specs that determine the overall performance of a hard drive. With access time, lower is better.

Drive	Max MB/s	Min MB/s	Access Time (ms)
Toshiba MK 1031GAS 100 GB 4200 RPM	28 MB/s	13 MB/s	18.7
Hitachi 4K80 80 GB 4200 RPM	30 MB/s	15 MB/s	20
Fujitsu MHU2100AT 100 GB 4200 RPM	32 MB/s	16 MB/s	20.1
Samsung MP0804H 80 GB 5400 RPM	32 MB/s	15 MB/s	17.9
Western Digital Scorpio WD800VE 80 GB 5400 RPM	34 MB/s	18 MB/s	18
Toshiba MK8026GAX 80 GB 5400 RPM	35 MB/s	19 MB/s	17.9
Seagate Momentus 5400.2 100 GB 5400 RPM	36 MB/s	18 MB/s	17
Hitachi 5K80 80 GB 5400 RPM	36 MB/s	18 MB/s	17.6
Hitachi 7K60 60 GB 7200 RPM	39 MB/s	19 MB/s	14.7

While faster RPMs do tend to indicate faster performance, as you can see by comparing the Fujitsu 4200 RPM and Samsung 5400 RPM, that isn't always the case. Also, look at the differences themselves. The average 5400 RPM drive is about 35 MB/s max while the average 4200 RPM drive is about 30 MB/s max throughput. This is a 15% difference... not a whole lot. It's even a bit less going from 5400 to 7200 RPM. Let's assume that it takes 3 seconds to open an application, and it is totally hard drive speed limited. This isn't really true of most real-world applications, but it gives us the best-case scenario. So if it takes 3 seconds on an average 5400 rpm drive, it will take 3.5 seconds on an average 4200 rpm drive and 2.6 seconds on the 7200 rpm drive. Keep in mind this is a best case scenario, and the real application loading performance difference will be smaller.