The SSD Anthology: Understanding SSDs and New Drives from OCZ
by Anand Lal Shimpi on March 18, 2009 12:00 AM EST- Posted in
- Storage
Be sure to read our latest SSD article: The SSD Relapse for an updated look at the SSD market.
The Prelude
I spent about three weeks working on my review of Intel’s X25-M SSD. Most of that was research and writing and re-writing to not only review the product but also to talk about the rest of the SSDs in the marketplace and their deficiencies. Truth be told, I spent more time working on SSDs that weren’t the X25-M than the Intel drive itself. The Intel drive just worked as it should, the rest of them didn’t.
If you read the article, you know I was pretty harsh on some of the SSDs out at the time and if you’ve ever used any of those SSDs, you know why. Needless to say, there was some definite fallout from that review. I’m used to negative manufacturer response after a GPU review, but I’m always a bit surprised when it happens in any other segment.
I took a day or two off after that review went live, I think it was a day. Afterwards, I immediately started working on a follow-up. There was a strange phenomenon a few people noticed, something I unfortunately picked up on after the review went live; if you filled the X25-M up and re-benchmarked it, it got slower. And I had no idea why.
A few weeks later, I had it figured out. But then Nehalem was right around the corner. I’d tackle it after that. But then a new batch of SSDs from OCZ and other vendors were almost ready. I told myself I’d do them all at the same time. Then CES happened.
The More Things Change, The More They Stay The Same
If you look at the SSD market today, you’d assume that it’s very different from what it was just six months ago when the X25-M launched. People are worried that the Intel drive has issues with degrading performance over time. Some vendors are now shipping “revised” JMicron drives with multiple controllers, supposedly fixing all of the problems I talked about last year.
I hate to break it to you guys. As different as the world may seem today, it’s all very much the same.
The Intel drive is still the best of the best. Yes, it, and other SSDs do get slower over time and later in this article I’ll explain why it happens and why it’s not as big of a deal as you’d think. The issues I complained about with the JMicron drives from last year are still alive and well today; they’re just somewhat occluded.
Delay after delay kept me from writing this article, but I believe it’s for the best. What went in to what you’re about to read is nearly six months of research, testing and plain old work with SSDs.
The timing couldn’t be more perfect. We’re about to see a new wave of SSDs hit the market and it’s time to separate the fact from the fiction, the benchmarks from reality and the men from the boys. The last time I wrote an article about SSDs I ruffled quite a few feathers. That’s never my aim, but we’ll see what comes of this one.
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KadensDad - Tuesday, October 27, 2009 - link
How do these drives fail? I have heard that they will just suddenly die, no more writes or reads possible. What I would like to know is what happens when it dies? Do you lose all data? Just can't write anymore? How does the OS respond? Any early warnings? What about e.g. CRC? How does possibility of data corruption compare to traditional SSD? What about RAID? Since the drives are electrical, not mechanical, this reduces the number of failure vectors and environmental concerns (e.g., ambient temperature over lifetime of the drive). Won't SSDs therefore fail closer together in time in a RAID configuration? This reduces the window of opportunity for fixing an array and also decreases the applicability of RAID, however marginal.adsmith82 - Monday, September 14, 2009 - link
I need to run HDDErase on an X25-M. No matter what bootable CD or flash drive I create, HDDErase does not see either of my SATA hard drives. I already disabled AHCI in BIOS. Also, I am using version 3.3. I know that 4.0 does not work with the X25-M.Can someone help me troubleshoot this please? Thanks.
gallde - Thursday, June 11, 2009 - link
You point out that TRIM will only work on deletions, not on overwrites. But, couldn't a smart controller look at blocks that have a majority of invalid pages and "trim" them as well, recovering clean pages as a background process?forsunny - Thursday, August 13, 2009 - link
Why not just make the SSDs capable of individual page erases instead of blocks? Problem solved.Ron White - Sunday, August 31, 2014 - link
Erasing the NAND transistor in an SSD requires such a large jolt of voltage that it would affect surrounding transistors.lyeoh - Friday, May 29, 2009 - link
Good and informative article.Regarding the shill tshen83 who claims that Anandtech cost the drive manufacturers millions of dollars in sales.
If that is true, Anandtech has saved customers millions of dollars.
Anandtech should care more about their readers losses than drive manufacturer losses. If Anandtech was a site for drive manufacturers and their shills we wouldn't be reading it.
To me, if the SSD drive manufacturers lose money, it's their own fault for building crap that has higher write latencies than old fashioned drives with metal discs spinning at 7200RPM or slower. Not anandtech's.
I can get higher sequential reads and writes by using RAID on old fashioned drives. It is much harder to get lower latency. So Anandtech did the right thing for OCZ.
Lastly, there might be a way of making your windows machine stutter less even with a crap SSD. Note: I haven't tested the actual effect on an SSD because I don't have an SSD.
Basically by default when Windows accesses a file on NTFS, it will WRITE to the directory the time of the access. Yep, it writes when it opens files and directories (which are just special files). That might explain the stuttering people see. For a lot of things, Windows has to open files.
Warning! There are reasons why some people or programs would want to know the last access time of files. Me and my programs don't (and I doubt most people would).
If you are sure that's true for you (or are willing to take the risk) set NtfsDisableLastAccessUpdate=1 as per:
http://technet.microsoft.com/en-us/library/cc75856...">http://technet.microsoft.com/en-us/library/cc75856...
poohbear - Sunday, April 26, 2009 - link
Brilliant article and very informative on these emerging technology. I wont be buying one anytime soon @ their prices, but good to know we'll FINALLY be replacing convential HDD which are the one component that have been pretty much the same since as far back as i can remember"SSDs have +5 armor immunity to random access latency"
rofl that's the best analogy i've seen on a hardware review site. is every comp geek a RPG geek @ heart?
Gootch - Sunday, April 19, 2009 - link
Great article. Realy made me understand what I need to look at before making the plunge. Mistakes and all, my compliments. As for value between the now seemingly drastically improved Vertex vs the X25-M, I compared prices between the two and per Gb, the Intell product for say an 80 Gb drive is Can $5.86/Gb, while the OCZ 60 Gb SSD is Can $6.81/Gb. Now that we are no longer comparing apples and oranges, I think we need to point out that the Intel product is not only faster and maintains it's performance edge better, but it is cheaper per Gb. At least in Canada. I have many OCZ products and I love the company and it's customer support. I can only hope that they will make their SSDs more competitive in the near future, because most consumers will pay the extra 70 bucks and go with the X25 when they pay attention to the numbers, both performance and price.Baffo - Saturday, April 11, 2009 - link
I could forsee a whole host of issues with encrypting SSD drives, not the least of which is essentially making the drive completely "used" outside of the drive slack space - which would be a temporary reprieve for the reasons discussed in this article. However, I could also see potential performance and lifetime issues since modern encryption uses streaming ciphers (e.g. an entire encrypted block - which may or may not conform to the physical block size will be changed for even one bit change within the block itself). Has anyone looked at the resultant effect on performance due to using encryption - it would be good to compare say Bitlocker, PGP, Checkpoint, and an open source encryption solution (Crypt or something like that?). This could actually become a real driver for moving to on-drive encryption where it would have the opportunity to optimize the encrpytion for the pro/cons of the SSD architecture.brandensilva - Friday, April 10, 2009 - link
Great article! I respect that OCZ made the necessary changes to make this drive work. I'd rather take a slightly slower drive if it meant consistent performance.If my hard drive started to stutter I'd flip out! I'm glad that they took the feedback and instead of selling faulty drives, that would ultimately hurt their brand, they decided to go back to the drawing board and iron out the kinks. I'm not expecting them to compare to Intel's 25-M per price or performance. They don't have nearly the cash or manufacturing capacity to compete with Intel but they do have that small business feel with receiving feedback and making improvements, which is important to customers.
Lets hope they continue to utilize that aspect of their business and further improve on their products and bring us some reliable SSD's in the future.