Avoid SSDs with Jmicron’s JMF602 Controller
Solid state drives (SSDs) are the latest in hot tech upgrades these days, and rightly so. SSDs add huge boosts in performance to a system that is HDD bound, and the storage subsystem of a computer is the weakest link in its performance.
It's no wonder that SSDs are becoming increasingly popular. However, not all SSD drives are made alike. Don't think that you'll get great performance just by swapping out your old HDD for a new SSD. The first thing to consider is whether or not you'll want a MLC (multi-layer cell) or SLC (single-layer cell) drive. MLC SSD drives store more data, but at the cost of read and write performance, with a big dip on write performance. SLC drives rule in speed, but currently come in smaller capacities.
No matter which type of SSD you decide to pick up, you will no doubt witness instant performance gains after installing your new drive. However, with SSDs, things aren't so simple. Because of the way SSDs work, you will witness a steep degradation in performance over time. The performance occurs from a combination of things, but not because of file defragmentation like on a regular disc-based HDD.
With a regular HDD, you can simply run a good defragmentation utility to optimize the drive back to optimized conditions, and immediately experience the performance gains. On an SSD, you should never defrag the drive due to wear and tear of the flash memory cells. But this is only part of the problem. Another big problem with many SSD drives on the market is their use of the Jmicron JMF602 drive controller.
We'll just go ahead and say it right here: the controller is terrible.
First, the Jmicron JMF602 controller only has a 16 KB of onboard cache. That's barely enough to do anything. Contrary to this, the controller that Intel uses, the PC29AS21A blows the Jmicron controller out of the water with 256 KB of cache. The Intel controller also has significantly better wear leveling and write combining algorithms.
During heavy use, the Jmicron controller will literally choke on incoming data, and consequently report back to the operating system that it's buffers are filled and writes and reads need to be queued up. This puts a hold on incoming and outgoing disk I/O, causing applications to hiccup and hang while the controller chugs along. Worst, the performance degrades significantly over time as the drive is used.
Recently, OCZ swapped out the Jmicron controllers in its drives in favor of Indilink's Barefoot controller, offering significantly better performance and cell management algorithms. Other manufacturers are following suit as well.
If you're in the market for an SSD, do a bit of research to find out if the drive uses a Jmicron controller. News from Jmicron is that its updated to a new revision of its SSD controller that is suppose to solve many issues. Save yourself the problem of testing out these claims and just avoid Jmicron-based drives altogether.
Also, it's the intel drive that has its performance reduced significatly over time because of it's complex wear-leveling algorithm. Moreso than the rest. http://pcper.com/article.php?aid=669
So, you have upwards of $1600 to toss into your storage devices. most people have about $1000 for their rig, sometimes more, sometimes less. SLC is the most expensive per megabyte, so I know you are paying less than $400 a pop for those, especially if you have had them long enough to become addicted to them.
They are great, wonderful, not fads and I will one day likely move to them or something that replaces them. For today though, they are not reliable, they are advancing too fast for me to spend the cash for one today that may be 1/4 the speed, storage space and longevity of one I could have paid half price for 6 months from now. For people with unlimited cash for these toys, they are well worth the cash, but for people who have more modest means, or just modest personalities, I think HDD is the way to go, today.
http://www.ocztechnologyforum.com/forum/forumdisplay.php?f=186 is a great place for info on SSD changes and tweaks to get the best performance from your device.
I agree with you. If you really do need that speed, and you make money off your computer, then it is the way to go, and replacing them a year from now with higher performing ones would be economically worth while. I guess we are in two different levels of the computer usage model. I am just a home user commenting on rigs, typically for things like gaming, and you seem to be a professional who might be into database management or something else that is heavily taxing on the storage system.
Awesome article, thank you for linking that!!!
Then what tech will?
There are already SSDs that can do 600MB write and 700MB read. Just like any technology, it's going to be expensive at first, but once it starts picking up speed, prices will go down.
Look at CDs, 20 years ago they were extremely expensive, and many believed them to unnecessary. Now a device that reads CD can be had for less than $10, and it costs less than a cent to press a CD.
Would it not make sense to tell us to check back later as you review this "New" controller to see if it stacks up? and Avoid Jmicron until that time.
EDIT.
I can edit and so can you
I assume your talking about the Fusion ioDrive for that kind of performence. We are testing these here at work, they are very nice. Too bad they are so damn expensive, we have already had one die on us. At least they didnt tell us we were using it too much like Dell did.
I wish we could edit comments.
http://www.ocztechnologyforum.com/forum/showthread.php?t=50376
Yes the controller may be crappy, but that (or similar) controller was standard on all SSD's of a couple of years ago!
It's not that the controller is crappy, it's that intel (and now other manufacturers) finally created some great controllers that improve performance greatly!
Still, when I buy my SSD, I will keep an eye out for the bad controller,and try not to buy it!