With the recent discovery by Anandtech that JMicron-based cheap SSDs can introduce multi-second lockup/lag in a system and that Intel’s ultra-pricey X25-M SSDs didn’t suffer from the problem, it was looking like folks that had to have an SSD and were willing to pay for it had a chance at salvation… not so fast.
PC Perspective did a long-term analysis of the Intel X25-M SSDs discovering that over time, what seems to be the algorithms built into the drive to improve it’s life span and reliability are actually acting against the performance of the drive — slowing it down over time.
You can see here from the PC Perspective’s Before and After benchmark how performance has degraded considerably before and after a certain amount of use:
PC Perspective has an excellent breakdown of how these disk algorithms work and how they can get confused during write-combining into a spiral of degraded performance right down the hole. It seems like either a complete disk wipe or a massive contiguous disk-write operation will reset the logic on the drive to get it back up to it’s 100 mb/sec glory, but in typical every day use you likely aren’t going to see that happen.
They finally provide a few workarounds for folks in this scenario and a path to the future we need to head towards for this to not be a problem anymore.
All I took away from this really in-depth article is that SSDs are not ready for prime-time and have another 2 years in the oven before you will be wanting to throw these things in every PC you have and/or want.
We apparently need Flash-aware file systems (SanDisk is work on ExtremeFFS for this) that treat disk read/write operations a bit differently, paying attention that Flash cell life is limited and after a certain number of erase cycles eventually fail. In addition to the new filesystems (hardly an easy task to get right on the first try) we need revised disk controllers so affordible SSDs are no longer a reliability and performance nightmare for us as well.
And if we are getting revised file systems and controllers, god knows there is an Operating System component that will eventually fit in there… we’ve got a long way to go before SSD technology settles down and everyone starts competing at price/performance levels — that’s when I will start caring.