jenflash :. Sapphire Paw

Booting from Flash Media: A Preliminary Benchmark

In October of 2005, I installed a Gentoo Linux system on a 512 MB Secure Digital (aka SD) card, with a few partitions mounted from a hard disk for extra space. After three days of effort, I was able to boot the system and do some benchmarking.

The flash card (a Sandisk UltraII) transfers at only ¼ the speed of the Seagate Barracuda IV hard drive that I was using, but without any moving parts, its access latency (the time between asking for and receiving information) is much lower. This means that, after a six-second forced delay to wait for the card reader to be ready for Linux to boot, the flash ended up being fast enough to catch up with the performance of a hard disk.

There are bigger, faster flash devices on the market, notably Lexar's JumpDrive Lightning. There are also faster hard disks, such as Western Digital's legendary Raptor. At least on paper, it would seem that pitting the Lightning against the Raptor would lead to similar results, only more quickly. The next generation of products in both lines is where things will get interesting. If current trends continue, the addition of NCQ to the new hard drives could allow them to pull ahead again due to the reduction in latency.

(Update: this was all written well before solid-state disks came to market.)