The “Break it Down” Blog

Not all solid state drives (SSDs) are created equal it seems. Taking a quick glance at the Newegg SSD product listings for 32GB drives, you can get an idea that there is something different between a $300 OCZ and a $600 Intel SSD.

A big thanks to Patrick Norton for sending this information in — it seems that some of the cheapest MLC (multi-level-cell) SSDs on the market right now utilize a unified JMicron-controller design with Samsung memory. Anandtech’s founder discovered 1-second long pauses with his computing experience on his MacBook after dropping one of the new OCZ drives into his laptop and set out to benchmark exactly what was going on. The result was a 17-page article breaking down SSDs in their entirety and discovering what the issue was.

As it turns out, MLC SSDs utilizing JMicron controllers have (what I would consider) a design flaw in them such that multiple write requests can queue up and completely starve the system of disk access for up to 1-second before the write is eventually serviced. This literally translates into 1-second pauses when doing simple tasks. In Anand’s case, he was sending IM messages (which cause a very small update of the chat log file) and was noticing a complete freeze of his computer for 1-second before responsiveness returned to the entire OS.

Taking a look at the chart above, IO Meter was used to test completely random 4KB writes on the disk over a period of time. Notice how JMicron-based SSDs (OCZ Core in this case) performance is less than that of a standard Seagate hard drive used in the comparison while the Intel X25-M destroys it with roughly 2725% higher performance?

That’s just insane.

For the time being it seems that the SSD industry is still figuring out how it wants to comoditize certain designs while enhancing others. Right now this looks like a total fail for the OCZ Core line to me, while Intel is doing everything right — unfortunately for us the price reflects that.

I would expect revised hardware models, controllers and a much more accessible price point this fall for SSDs in general with them dominating sales in 2010.

In the mean time, don’t hop in the cheap-SSD sandbox just yet… you might not get the performance you are expecting.