Analysis

posted on 30 April 2008 07:45

All sizzle and no steak: a counter to the flash solid state drive (SSD) excitement is emerging, saying that they don't actually boost noteboook computer performance much at all.

The argument in favour of flash SSD use says it is more reliable than disk - no moving parts, faster than disk - no head latency, greener than disk - no spinning platters, and so all round better than disk even though it is much more expensive per giagabyte.

SSD's performance advantage is demonstrated by its use to speed up I/O-bound applications in datacentres. But the main SSD I/O booster rockets are fuelled with faster DRAM, such as Texas Memory Systems' Ramsan and The Violin Memory Appliance.

Phase one of the flash entry into notebooks and PCs was as a hard drive cache, either in the hard drive clamshell or on the motherboard, with Microsoft software technology to take advantage of it to shorten boot times and reduce hard disk drive (HDD) write levels. Neither benefit actually happened much and the hybrid flash cache/HDD idea has become discredited.

Now notebooks are available with flash SSDs instead of a hard drive, like the MacBook Air, and we all mostly expected them to out-perform their HDD tortoise rivals with faster boots, faster applications and longer battery life. Only they don't.

Over in storage blog land the Storage Mojo (Robin Harris) asks if the expected flash advantage is actually a mirage.  Yes, boot is faster but battery life gets extended by maybe ten minutes and app execution times hardly vary. He suggests that flash is just not worth the extra cost.

A ComputerWorld review suggests the same conclusion - mixed results with no clear winner, not even on boot timing.

It appears, in the absence of firm manufacturer's test results that notebook computers with flash may not actually do significantly better than HDD-equipped ones unless the application is I/O-bound. Boosting your notebook computer's DRAM and CPU could sort many performance problems as not many notebook apps are database I/O-bound.

Unless flash SSDs significantly cut boot and application start-up times, say by 30 percent or more, then the flash notebook market will be all sizzle and no steak; a mirage that diasappears as you get closer to it.

^{[Chris Mellor.]}