News

posted on 03 July 2008 10:39

A hardware test has found that flash memory solid state drive use (SSD) reduces notebook computer batter life instead of extending it.

Toms Hardware reports the results of a detailed test looking at several flash drives and their performance when installed in a Dell Latitude D630 notebook. The single level cell (SLC) SSDs did their expected I/O speed thing compared to a 2.5-inch, 7,200rpm Hitachi GST 7K200 notebook hard drive but, astoundingly, they used up battery power faster.

The speed improvement was impressive with one test run time being an hour slower on the hard drive set-up.

The tested flash drives were:-

- Crucial SSD, 32 GB,
- Memoright MR25.5-032S, 32 GB,
- Mtron Flash SSD, 32 GB,
- Sandisk SSD 5000, 32 GB.

When fitted with the hard drive, the notebook recorded a battery run time of seven hours and three minutes. The Crucial SDD delivered six hours and three minutes, one hour less. The Memoright six hours and 38 minutes. An Mtron flash drive provided a battery run time of six hours and six minutes. The SanDisk was best with seven hours and two minutes, but still not better than the hard drive.

The review speculated that hard drives only use maximum power when moving their read/write heads, with the rest of the time being spent in a near-idle state. SSDs use full power whenever they are carrying out I/O and they don't have power-saving circuitry built in, resulting in them using more power than the 2.5-inch hard drive.

What is obvious from this test result is that not one single supplier of the flash drives tested has made available detailed figures backing up their extended battery life claims. It might even be the case that none of them has actually carried out an equivalent test, relying instead on the raw energy consumption figures and assuming that they translate into real life battery power savings.

They don't. Notebooks should use SSDs for I/O speed improvements alone, not for imagined and illusory battery life extension.

^{[Paul Roberts, news editor.]}