Understanding Hard Drive Performance

Interface Bandwidth

As expected, Serial ATA has a huge bandwidth advantage over UltraATA. Yet the differences are irrelevant in everyday life, as the drives do not hit the bandwidth bottleneck of UltraATA/100, which clearly is 85 MB/s in case of the 7200.10. SATA/300 may send almost 200 MB/s over the wires, but this only reflects the performance at which data is retrieved from a drive's cache memory, not the platters themselves.

Access Time

These are obvious results: the drives with the most capacity waste had the quickest access times, as the read/write heads have a shorter operating range due to the unused inner storage areas. However, we did not observe this tendency within the UltraATA drives, where access times seem to be slightly longer across the product line.