The SSD Anthology: Understanding SSDs and New Drives from OCZby Anand Lal Shimpi on March 18, 2009 12:00 AM EST
- Posted in
There’s no skirting the issue: even the best SSDs lose performance the more you use them. Eventually their performance should level off but what matters the most is how their performance degrades.
In using the X25-M I’d say that the performance drop was noticeable but not a deal breaker - and the data tends to agree with me. With average write latencies still well under 1ms, the drive maintained its most important performance characteristic - the ability to perform random accesses much faster than a conventional hard drive.
Keep in mind that with the cost per GB being as high as it is, these SSDs aren’t going to be used for large file storage in a desktop or notebook. You’re far more likely to use one as your boot/applications drive. As such, what matter the most aren’t peak transfer rates but rather fast access times. On a well designed drive with a good controller, peak transfer rates may fall over time, but latency remains good.
You end up with a drive that still manages to be much faster than the fastest 3.5” hard drives, but slower than when you first got it.
If, however, you aren’t ok with the performance drop over time then it’s worth considering what your options will be. When drives ship with ATA-TRIM support, hopefully late this year, they will do a better job of staying closer to their maximum performance. But the problem won’t be solved completely. Instead, what we’ll need to see is a more fundamental architectural change to eliminate the problem.
I still believe that a SSD is the single most effective performance upgrade you can do to your PC; even while taking this behavior into account. While personally I wouldn’t give up a SSD in any of my machines, I can understand the hesitation in investing a great deal of money in one today.
Intel’s X25-M: Not So Adaptive Performance?
The Intel drive is in a constant quest to return to peak performance, that’s what its controller is designed to do. The drive is constantly cleaning as it goes along to ensure its performance is as high as possible, for as long as possible. A recent PC Perspective investigation unearthed a scenario where the X25-M is unable to recover and is stuck at a significantly lower level of performance until the drive is secure erased once more.
There’s not much I can say about the issue other than I’ve been working with Intel on it very closely and it’s not something I’m overly concerned about at this point. I can replicate the PC Perspective data but not by using my machine normally. Through the right combination of benchmarks I can effectively put the drive in a poor performance state that it won’t recover from without a secure erase. I should also mention that I can do the same to other drives as well.
I’ll be able to say more soon but for now just hang tight. I’d venture a guess that Intel would not leave its most loyal customers out in the cold after spending $400 - $800 on a SSD. I can’t speak for Intel but like I said, stay tuned.