Analysis: The Impact Of Shifting From 512 Byte To 4 KB Sectors

4 KB Sectors: Toshiba MK7559GSXP (750 GB)

This is the latest 2.5” SATA drive from Toshiba and it happens to be based on a 4 KB sector size, making it perfect for a comparison with the 640 GB predecessor. We expected throughput to increase, which it does: a 107 MB/s peak and 81 MB/s average read transfer rate are excellent results for a 2.5” hard drive and actually not far away from the performance numbers of 3.5” drives that spin at 5400 RPM. Clearly, the performance gap between the form factors is getting a bit smaller.

As already mentioned on the previous page, we found that the new drives deliver reduced I/O performance for as long as the logical 512 byte sectors are aligned to the physical 4 KB units. The differences mainly result in increased data density and the fact that 2.5” drives are designed for mobile applications in notebooks or laptops. Therefore, a certain performance penalty in favor of efficiency is usually expected.

In fact, there are a few more benchmarks where the new drive is weaker than its 640 GB predecessor with regular 512 byte sectors. PCMark Vantage is one of them. Still, the difference isn’t as noticeable as you would think, as both 5400 RPM drives weren’t designed for the performance segment.