Intel X25-M SSD: Intel Delivers One of the World's Fastest Drives
by Anand Lal Shimpi on September 8, 2008 4:00 PM EST- Posted in
- Storage
How Long Will Intel's SSDs Last?
SSD lifespans are usually quantified in the number of erase/program cycles a block can go through before it is unusable, as I mentioned earlier it's generally 10,000 cycles for MLC flash and 100,000 cycles for SLC. Neither of these numbers are particularly user friendly since only the SSD itself is aware of how many blocks it has programmed. Intel wanted to represent its SSD lifespan as a function of the amount of data written per day, so Intel met with a number of OEMs and collectively they came up with a target figure: 20GB per day. OEMs wanted assurances that a user could write 20GB of data per day to these drives and still have them last, guaranteed, for five years. Intel had no problems with that.
Intel went one step further and delivered 5x what the OEMs requested. Thus Intel will guarantee that you can write 100GB of data to one of its MLC SSDs every day, for the next five years, and your data will remain intact. The drives only ship with a 3 year warranty but I suspect that there'd be some recourse if you could prove that Intel's 100GB/day promise was false.
Just like Intel's CPUs can run much higher than their rated clock speed, Intel's NAND should be able to last much longer than its rated lifespan
It's also possible for a flash cell to lose its charge over time (albeit a very long time). Intel adheres to the JEDEC spec on how long your data is supposed to last on its SSDs. The spec states that if you've only used 10% of the lifespan of your device (cycles or GB written), then your data needs to remain intact for 10 years. If you've used 100% of available cycles, then your data needs to remain intact for 1 year. Intel certifies its drives in accordance with the JEDEC specs from 0 - 70C; at optimal temperatures your data will last even longer (these SSDs should operate at below 40C in normal conditions).
Intel and Micron have four joint fabs manufactured under the IMFT partnership, and these are the fabs that produce the flash going into Intel's SSDs. The 50nm flash used in the launch drives are rated at 10,000 erase/programming but like many of Intel's products there's a lot of built in margin. Apparently it shouldn't be unexpected to see 2, 3 or 4x the rated lifespan out of these things, depending on temperature and usage model obviously.
Given the 100GB per day x 5 year lifespan of Intel's MLC SSDs, there's no cause for concern from a data reliability perspective for the desktop/notebook usage case. High load transactional database servers could easily outlast the lifespan of MLC flash and that's where SLC is really aimed at. These days the MLC vs. SLC debate is more about performance, but as you'll soon see - Intel has redefined what to expect from an MLC drive.
Other Wear and Tear
With no moving parts in a SSD, the types of failures are pretty unique. While erasing/programming blocks is the most likely cause of failure with NAND flash, a secondary cause of data corruption is something known as program disturb. When programming a cell there's a chance that you could corrupt the data in an adjacent cell. This is mostly a function of the quality of your flash, and obviously being an expert in semiconductor manufacturing the implication here is that Intel's flash is pretty decent quality.
Intel actually includes additional space on the drive, on the order of 7.5 - 8% more (6 - 6.4GB on an 80GB drive) specifically for reliability purposes. If you start running out of good blocks to write to (nearing the end of your drive's lifespan), the SSD will write to this additional space on the drive. One interesting sidenote, you can actually increase the amount of reserved space on your drive to increase its lifespan. First secure erase the drive and using the ATA SetMaxAddress command just shrink the user capacity, giving you more spare area.
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mindless1 - Thursday, September 11, 2008 - link
Sometimes the cure is worse than the problem.Gannon - Tuesday, September 9, 2008 - link
Don't worry derek I still heart you guys! :PHere's some cool software to check out (they have free trial version)
http://www.whitesmoke.com/landing_flash/free_hotfo...">http://www.whitesmoke.com/landing_flash...otforwor...
Maybe it will help escape complaints from the grammar nazi's, I think a lot of grammar is BS anyway. Language evolves constantly. It's a flexible tool to communicate.
Nihility - Monday, September 8, 2008 - link
An excellent review. The benchmark results were always confusing in the past. No one would try to explain why an SSD with seemingly superior specs can't outperform a 7200 drive in media test. Thanks for putting the time in to resolve this issue.As for buying a drive like that, the price is still too steep for me to consider and you definitely made it clear that buying a jmicro SSD is out of the question.
As for further testing, I'm very interested in seeing how a good SSD performs as an external drive over USB. The robustness and sturdiness of the drive is very important for something you lug around. We all know how bad bandwidth is over USB but I wonder how the latency will fair.
Keep up the good work.
kmmatney - Monday, September 8, 2008 - link
One of the other reviews I read said this SSD's controller will learn hard drive usage patterns, and get faster over time. Any tests of this feature?leexgx - Monday, September 8, 2008 - link
not sure how thay can lerni did wunder why thay never put any DRAM buffer on SSD drives as i was expecting SSD to suffer badly from lack of buffer any MLC drives basicly suck (16kb buffer per flash chip) unless its the intel MLC drive lol or an SLC drive seem mostly ok, but an intel SLC going to rock when thay get tested
Anand Lal Shimpi - Monday, September 8, 2008 - link
The Intel drive will learn hard drive usage patterns however it does so over an extremely long period of time, not something I could develop a test for in my time with the drive.Take care,
Anand
whatthehey - Monday, September 8, 2008 - link
...that doesn't think too much about HDD performance, particularly when we're talking about insane prices. Sure, rebooting and reloading all of your apps will feel much faster. Personally, when I reboot I walk into the kitchen or bathroom, walk back a few minutes later, and I don't notice the delays. Not to mention, I only reboot about once a month (usually when nVidia releases a new driver that I need to install).Another major problem I have is the tests as an indication of the "real world". Take the whole antivirus thing. I hate AV software and software firewalls, which is why I don't use Norton, AVG, Avast, McAfee or any other product that kills performance, sucks up memory, and only prevents virii/trojans after an update. AV software is just a BS excuse to pay a $60/year subscription and get nags every time your subscription expires. So there's on "real" scenario I don't ever encounter.
Archive extraction can be pretty disk intensive as well, but how often do you need to extract a 5GB archive? Okay, so let's say you're a pirate and you do that daily... great. Now you can extract faster, but you have an SSD that can only hold 14 or so large archives. It's a nice illustration of SSDs being faster, but it's completely impractical. I have a 1TB drive just for all the movies, images, music, and disc images I have floating around.
The tests show that SSDs can help a lot, but I for one use capacity far more. Between several games, my standard apps, and Vista I think I would use most of the 80GB. Then I think of the price and I could grab a couple VelociRaptors or even four 1TB Samsung F1 drives. I'll be truly impressed when I can get at least 320GB of SSD for less than $200. Actually, it's more like I want a good SSD with a reasonable capacity for under $100. Until then I'll just stick with my slower drives and avoid worst-case situations where HDD performance is a problem as much as possible.
The article was good, and I appreciate the info on the MLC issues with JMicron. That confirms my suspicion that inexpensive flash drives are worse than standard mechanical drives. Intel has addressed the problem, but price is now back to where we were last year it seems. I guess the real problem is that I'm just not enough of an "enthusiast" to spend this much money on 80GB of storage... not counting stuff like that old 4GB hard drive back in the day that set me back over $200. Give it a few more cycles and I think I'll be ready for SSDs.
PS - Also, who cares about $600 CPUs when you can buy $200 CPUs and overclock to higher performance levels? I don't think we'll ever see overclocked SSDs or HDDs.
DerekWilson - Tuesday, September 9, 2008 - link
i wouldn't be so sure about not seeing overclocked SSD ...as this article points out, intel puts a focus on reliability ... but to do so they do sacrifice performance. the voltage applied to the transistors to store data is calibrated to write the cells quickly while maintaining a good life span. a higher voltage could be applied that would allow the cells to be written faster but would reduce the number of writes that a cell could handle.
if intel says 100gb a day for 5 years ... i don't need that by a long shot. i would be very willing to sacrifice a lot of that for more speed.
i actually spoke with intel about the possibility of overclocking their ssd drives at idf -- it is something that could be done as it is controlled via the firmware of the drive. if intel doesn't convolute their firmware too much or if they allow enthusiasts to have the necessary control over settings at that level we could very well see overclocked SSDs ...
which would be very interesting indeed.
shabby - Monday, September 8, 2008 - link
I was so close in buying one of those ocz drives, in fact the reason i didnt buy it was because it was a special order that took 2 weeks.Excellent write up, especially about the jmicron/mlc "glitch".
OCedHrt - Monday, September 8, 2008 - link
Any reason why the WD GP drive does so well in the multitasking test? Even better than the VelociRaptor?