The durability of SSD drives

g00ey

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During the past half year or so I have seen more and more people getting SSD drives for their computers as the prices are on a steady decline. But I have not seen any useful information about how these drives address the durability issues that are involved with flash based storage media.

I don't doubt that SSD storage media is useful as a storage device but I have my doubts about using it as a system drive (unless the operating system is an "embedded" system where it loads itself into RAM during startup so as to minimize read/writes to the drive).

The biggest issue of installing Windows on such a drive is the page file which is virtually impossible to disable (yes you can set it to 0 but it comes back on once the system runs out of physical memory which always happens eventually). I believe that a page file can wear out a flash drive with in months of frequent use.

I know that Windows 7 has introduced something that is called trimming which means (if I understand correctly) that the read/write access is randomized so as to even out the read/write wear on all sectors of the drive. But how does that really add to the durability of the flash drive? And what if I want to stick with XP/XP-x64 that from what I know does not support trimming?
 
This Anandtech article has some excellent information on the issues you're concerned about.

The long and the short of it is that if you buy an SSD with a well-implemented controller, you shouldn't have any worries under normal use. Intel claims that their SSDs will last for "at least" 5 years even if you write 20GB/day of data to them. Based on the write rate I've seen on my own Windows 7 system, that means my drive will last over 20 years.

If you use an OS that doesn't support TRIM, there are utilities available which will go through and mark the unused sectors for you. For example Intel has a software package called the "SSD Toolbox" which you can manually run from time to time, rather similar to the way you would have defragmented a mechanical hard drive.
 

g00ey

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Thanks for the link, that was a very interesting read!

So the longevity issue has nothing to do with TRIM, TRIM is merely a measure to sustain write performance.

I really hate JMicron pruducts, I've had two different motherboards with JMicron based SATA controllers and BIOS fails to identify disks that use this controller on both boards. Any JMicron based SSD sucks in performance in all tests I've read so far, I wonder if this company will last much longer.

The Kingston V+ series with the Toshiba T6UG1XBG controller seems to be a promising alternative for the desktop market.
 

Well there's an indirect relationship between them because SSDs do "wear levelling" in order to minimize the write cycle limitation on the flash memory cells, and as a result of that TRIM is used in order to keep a supply of fresh, empty cells to allow writes to be performed quickly.
 

tomasb

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I had two Intel 320 series 160GB drives in two months. First broke up in 2 weeks. Both gone the same way, BIOS doesn't see it anymore = all data lost in a milisecond. Lost many hours of my work (= money). Intel never again. But i will try Corsair Force GT with 2 mil. hours of MTBF (Intel doesn't claim any MTBF or anything like that!).

Hope this helps.
 

blackhawk1928

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Are you sure it did not start, because you messed with bios and connections? Every time I mess with my storage device connections, I need to mess with my BIOS to get the SSD into my boot list and then switch it to primary.

Either way, I've been operating on a X-25M for almost two years now and it works excellent.
 

PotatoApple

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MLC flash made with a smaller process yield higher density drive but it also have negative impact on write endurance. current MLC cell can encode 2 bits. This means a 128GB contains only 128GB / 2 = 64GB worth of cells. 25nm MLC chips are typical rated for 5000 read/write cycle. Given write rate of about 20GB a day and perfect write leveling. We can approximate how long the SSD will last

64GB x 5000 / (20GB/day) = 16000 days

This is approximately 44 years give a and take a few years it should last 40 years.
But this is not the case......... its more like a few years < than 5

One problem is conventional OSes will page memory on to your hard drive. If you do alot of intense video editing or memory intensive apps make sure you have enough ram to minimize paging.

Also reading from flash can also wear it out because periodic reading of the same NAND Cell can actually disturb surrounding cells in other to keep the values in the surround cells the SSD controller need to track read counts and periodic do rewrites to neigbour cells to decrease reading error.

TRIM and wear leveling is less effective as you fill up your SSD.

For a gamer SSD does nothing to your actual in game performance, it only launches the game faster. And if you are a programmer like me that does alot of compling builds and deleting builds > 1GB it will wear down the drive in no time. Given the high dollar/GB on SSD and the performance degration and durability issue, I don;t think SSDs are worth it at the moment.