SSD durability question

[Martijn2]

I am thinking about buying an SSD to replace my HDD. Am I right in thinking that a larger SSD will last much longer than one with less space? Let's say you have a 64 GB SSD with Trim with an average of 10.000 writes. So in theory, this drive will last 64 GB * 10.000 writes = 640.000 GB = 640 TB of total data? With this calculation, a 128 GB drive should last twice as long (1280 TB)?

[moontan]

if you're in no rush i'd wait a few months to see where this tech is going.
from what i've gathered the amount of write operations is much less than what the marketing and specs claim.

and you'd get better prices as well...

[BoerenkoolMetWorst]

I thought the limited amounts of write operations was a problem of the past.

[moontan]

i have been searching and Googling for the past half hour but up to date information about this subject (reduced life caused by write operations) seems pretty rare.

i'll keep on looking and post here if i find something.

[Martijn2]

Originally Posted by moontan

if you're in no rush i'd wait a few months to see where this tech is going.
from what i've gathered the amount of write operations is much less than what the marketing and specs claim.

and you'd get better prices as well...

Yeah, I know that the latest SSD's are build with a smaller size (25nm I think), and can only have 5000 writes or so.

I thought the limited amounts of write operations was a problem of the past.

Nope, the problem is reduced with TRIM, but is still there.

[tekkaman]

I wouldn't trust SSD yet. I think it's the same concept as a flash drive. And haven't you heard many people loosing their important work in flash drives ? Or like when windows wants to force you to format no matter what, and you loose all your data.

[BoerenkoolMetWorst]

Originally Posted by Martijn2

Nope, the problem is reduced with TRIM, but is still there.

Ok, thanks.

[Triple Helix]

Good subject I was wondering the same as I wanted to get 2 for my new Laptop! So it looks like it's best to wait for better reviews as I don't see that many!

TH

[Raza0007]

Originally Posted by Martijn2

I am thinking about buying an SSD to replace my HDD. Am I right in thinking that a larger SSD will last much longer than one with less space? Let's say you have a 64 GB SSD with Trim with an average of 10.000 writes. So in theory, this drive will last 64 GB * 10.000 writes = 640.000 GB = 640 TB of total data? With this calculation, a 128 GB drive should last twice as long (1280 TB)?

This is not how it works. The 10,000 write cycles are per cell. So on average, each cell of a MLC SSD can withstand 10,000 repeated write cycles before failing. TRIM helps in making sure that certain cells are not written to over and over again at the expense of other cells, but this does not mean a double capacity SSD will last twice as long. However, for a fixed amount of data, a larger capacity SSD is expected to last longer than a smaller capacity SSD, but in real life you can not keep the amount of data fixed. When you get a bigger hard drive, you tend to fill it with more data. It is just human nature.

If you are looking for a long lasting SSD then why not go with a SLC SSD? They have 100,000 writes per cell on average. However, they do cost a lot more.

[Martijn2]

Originally Posted by Raza0007

This is not how it works. The 10,000 write cycles are per cell. So on average, each cell of a MLC SSD can withstand 10,000 repeated write cycles before failing. TRIM helps in making sure that certain cells are not written to over and over again at the expense of other cells, but this does not mean a double capacity SSD will last twice as long. However, for a fixed amount of data, a larger capacity SSD is expected to last longer than a smaller capacity SSD, but in real life you can not keep the amount of data fixed. When you get a bigger hard drive, you tend to fill it with more data. It is just human nature.

If you are looking for a long lasting SSD then why not go with a SLC SSD? They have 100,000 writes per cell on average. However, they do cost a lot more.

Thank you! But some things are still not really clear. I understand that one MLC lasts about 10.000 writes, but if you have twice as much space (let's say 64 -> 128 GB) to write in, it would take longer for one cell to get written 10.000 times since you have more cells to write first to right? I guess you answered this question with "However, for a fixed amount of data, a larger capacity SSD is expected to last longer than a smaller capacity SSD, but in real life you can not keep the amount of data fixed. When you get a bigger hard drive, you tend to fill it with more data. It is just human nature. "

[xxJackxx]

TRIM does nothing for drive life, it is for speed. It erases the deleted cells so it does not have to be done when writing. Wear Leveling is for increasing the drive life by spreading the writes around the drive. A larger drive would last longer with the same amount of data, but I know if I had a larger drive I would not keep it 75% empty. I have a 120GB SSD drive in each of my machines and just use them as a normal drive. If they burn up I will go back to mechanical drives. If they hold up well I will stick with them. I personally do not find the SSD so fast that I could not go back. Considering the price and the space I have lost I do not feel it was a worthwhile upgrade.

[Raza0007]

This is the reason I have not bought a SSD for personal use myself. The cost to benefit ratio is still not good enough. This wear-leveling is controlled by the SSD controller and you can never be sure that it is doing its job 100%, even if it is doing its job. So, when people ask me which SSD to choose as a boot drive I always recommend a SLC based SSD.

[Seer]

In my local shop I can get some 64GB Kingston's (V-series) for 100euros/pc. I don't know about 1000s of writes, wear-leveling, MLC, SLC and such, but they come with a 36-month warranty. This deal looks pretty fair to me.
As I am building a new rig, I was thinking of setting up one of these as my primary drive and use external (3x2TB) for storage. SSD would be the only drive in the rig, one partition for the OS and another for swaps and such. So if and when SSD dies, I would just buy a new one and restore an image. Given the price above, what do you guys think about the idea? Obviously a noob with SSDs.

(I was about to open a new thread, but seemed appropriate to post here. If not, please move/open new.)

[Raza0007]

Originally Posted by Seer

Given the price above, what do you guys think about the idea? Obviously a noob with SSDs.

The price seems fair for a 64 GB SSD. At this price it is definitely a MLC based SSD, so depending on your usage it might last longer than 3 years or might last just 3 months. The warranty will probably cover only if there is some factory defect in the SSD. I doubt it will cover the NAND flash cells that have become unusable due to excessive write cycles.

If you do go with this SSD, my recommendation is that you keep a single partition on the SSD and keep the swap file in the that partition. Since the swap file is written to multiple times in a session, this will give wear-leveling algorithms more room to move the swap file between different NAND cells. If you move the swap file to its own smaller dedicated partition then the wear-leveling algorithm will get restricted to that smaller partition only, and those cells will eventually fail due to excessive write cycle.

I am basing the above advice on the assumption that the wear-leveling algorithm can not shift data blocks over different partitions, although, to date, I have been unable to find any credible reference on it. But common sense dictates that wear-leveling must be restricted to cells within a partition.

[SKA]

Raza0007

Which brands/models of SLC SSD do you recommend (if price not a factor) ?
For notebooks and for desktops ?

Thanks
SKA

[Seer]

Originally Posted by Raza0007

The warranty will probably cover only if there is some factory defect in the SSD. I doubt it will cover the NAND flash cells that have become unusable due to excessive write cycles.

You may be right, I wasn't thinking about that. Will have to check.

If you do go with this SSD, my recommendation is that you keep a single partition on the SSD and keep the swap file in the that partition. Since the swap file is written to multiple times in a session, this will give wear-leveling algorithms more room to move the swap file between different NAND cells. If you move the swap file to its own smaller dedicated partition then the wear-leveling algorithm will get restricted to that smaller partition only, and those cells will eventually fail due to excessive write cycle.

I am basing the above advice on the assumption that the wear-leveling algorithm can not shift data blocks over different partitions, although, to date, I have been unable to find any credible reference on it. But common sense dictates that wear-leveling must be restricted to cells within a partition.

Yes, my common sense tells the same, I can see your point. Thanks, good info.

[Martijn2]

Originally Posted by xxJackxx

TRIM does nothing for drive life, it is for speed. It erases the deleted cells so it does not have to be done when writing. Wear Leveling is for increasing the drive life by spreading the writes around the drive. A larger drive would last longer with the same amount of data, but I know if I had a larger drive I would not keep it 75% empty. I have a 120GB SSD drive in each of my machines and just use them as a normal drive. If they burn up I will go back to mechanical drives. If they hold up well I will stick with them. I personally do not find the SSD so fast that I could not go back. Considering the price and the space I have lost I do not feel it was a worthwhile upgrade.

Aah thank you, I confused the two. I'm now thinking about buying a Seagate momentus XT instead (both HDD and 4GB SLC ssd), but I'm reading very mixed reviews about it (noise/vibrations/random spindowns). Btw, TRIM is only useful for the writing speed right? I figure that reading the data stays the same speed (not that booting will go slower over time or whatever).

[J_L]

Thanks for posting lots of info. Going to buy a SLC SSD in the future.

[xxJackxx]

Originally Posted by Martijn2

Aah thank you, I confused the two. I'm now thinking about buying a Seagate momentus XT instead (both HDD and 4GB SLC ssd), but I'm reading very mixed reviews about it (noise/vibrations/random spindowns). Btw, TRIM is only useful for the writing speed right? I figure that reading the data stays the same speed (not that booting will go slower over time or whatever).

TRIM is only useful for write speed. Read speed should never slow down.The reviews for the Momentus XT are often good but the real world feedback that I have seen often says there is little benefit to buying one. The last statistics I saw showed Seagate as having the highest failure rate. Buy what you like, but do plenty of research before doing so.

[Raza0007]

Originally Posted by SKA

Raza0007

Which brands/models of SLC SSD do you recommend (if price not a factor) ?
For notebooks and for desktops ?

Thanks
SKA

Are you asking for actual model numbers? If you are asking for brands, I would go with either Intel or Samsung SSD. Both have been making good quality ssd's for a long time. Perhaps you already know that Sandisk, Kingston, Corsair and maybe OCZ use Samsung NAND flash chips inside their ssd's. So, they are basically Samsung drives.

See here for some idea about the capacity vs price of a SLC SSD.

If you want some specific model let me know. I last researched about SSD in October last year as I was planning to buy one during the new year sales but then decided against it. So my information about latest SSD is not good at the moment.

[SKA]

Thanks Raza0007

As I am outside USA, was looking for reliable sources to get these. (Newegg does not ship overseas).

Your tips are appreciated, seems only Intel and WesternDigital (WD) have SLC models to offer .

SKA

[Raza0007]

Here is a valuable resource for anybody interested in SSD. This website is dedicated to SSD and people who use SSD. If someone is shopping for a new SSD this should be the starting point for them. Check out their forums too.


For SKA,
Here is an article/post about various brands of SSD on market today. I hope you find it useful.

[SKA]

Raza0007

Great links - thanks !

SKA

[Matsen]

Hi there,

this is a very interesting thread - I've been looking for information on durability, but there seems not to be that much out there. I must though admit, that I'm simply a dumb user, not at tech wize. Hence, many thanks for the link! This has already helped me a lot.

However, (and even though I probably a couple of lol's) I would be glad about some more info for "users". Can anyone help?

- If I buy a laptop for normal office use using an Intel or Samsung MLC SSD of let say 128 GB as the main drive (i.e. Win 7 OS, applications and swapfile on the SSD; user files stored on server or an external HDD), how long will that last? 1 yr? 2 yrs? 5?

- Any idea or at least rough guess? Would adding more RAM to reduce the size of the swapfile help to enhance longevity of the SSD?

Thanks a lot for your help!

[Triple Helix]

Very good reviews on this SSD! Mushkin Enhanced Callisto Deluxe

http://www.newegg.ca/Product/Product...82E16820226153

And on this one also: G.SKILL Phoenix Pro Series

http://www.newegg.ca/Product/Product...82E16820231379

TH