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
Final Words
I began this article with a recap of my history with SSDs, stating that the more things change, the more they stay the same. Honestly, today, the SSD world isn't much different.
Drives are most definitely cheaper today; the Intel X25-M originally sold at close to $600 for 80GB and is now down in the $340 - $360 range. The Samsung SLC drives have lost their hefty price tags and are now just as affordable as the more mainstream MLC solutions.
But the segmentation of the SSD market still exists. There are good drives and there are bad ones.
Ultimately it all boils down to what you optimize for. On its desktop drives, Intel chose to optimize for the sort of random writes you’d find on a desktop. The X25-E is much more resilient to the workload a multi-user environment would throw at it, such as in a server and thus carries a handsome price tag.
At first glance it would appear that Samsung’s latest controller used in the preview OCZ Summit drive I tested optimizes for the opposite end of the spectrum: sacrificing latency for bandwidth. As the Summit was used more and more, its random write latency went up while its sequential write speed remained incredibly high. Based on these characteristics I’d venture that the Summit would be a great drive for a personal file server, while the Intel X25-M is better suited as a boot/app drive in your system.
I’d argue that Intel got it “right”. Given the limited sizes of SSDs today and the high cost per GB, no one in their right mind is using these drives for mass storage of large files - they’re using them as boot and application drives, that’s where they excel after all.
Over the past year Intel continually claimed that its expertise in making chipsets, microprocessors and generally with the system as a whole led to a superior SSD design. Based on my tests and my own personal use of the drive and literally every other one in this article, I’d tend to agree.
OCZ and Indilinx initially made the mistake of designing the Vertex and its Barefoot controller similarly to the Samsung based Summit. It boasted very high read/write speeds but at the expense of small file write latency. In the revised firmware, the one that led to the shipping version, OCZ went back to Indilinx and changed approaches. The drive now performs like a slower Intel drive; rightfully so, as it’s cheaper.
While I wouldn’t recommend any of the JMicron based drives, with the Vertex I do believe we have a true value alternative to the X25-M. The Intel drive is still the best, but it comes at a high cost. The Vertex can give you a similar experience, definitely one superior to even the fastest hard drives, but at a lower price. And I’ll spare you the obligatory reference to the current state of the global economy. The Samsung SLC drives have come down in price but they don't seem to age as gracefully as the Intel or OCZ Vertex drives. If you want price/performance, the Vertex appears to be the best option and if you want all-out performance, snag the Intel drive.
The only potential gotcha is that both OCZ and Indilinx are smaller companies than Intel. There’s a lot of validation that goes into these drives and making sure they work in every configuration. While the Vertex worked totally fine in the configurations I tested, that’s not to say that every last bug has been worked out. There are a couple of threads in OCZ’s own forums that suggest compatibility problems with particular configurations; while this hasn’t been my own experience, it’s worth looking into before you purchase the drive.
While personally I'm not put off by the gradual slowdown of SSDs, I can understand the hesitation. In the benchmarks we've looked at today, for the most part these drives perform better than the fastest hard drives even when the SSDs are well worn. But with support for TRIM hopefully arriving close to the release of Windows 7, it may be very tempting to wait. Given that the technology is still very new, the next few revisions to drives and controllers should hold tremendous improvements.
Drives will get better and although we're still looking at SSDs in their infancy, as a boot/application drive I still believe it's the single best upgrade you can do to your machine today. I've moved all of my testbeds to SSDs as well as my personal desktop. At least now we have two options to choose from: the X25-M and the Vertex.
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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.