# Affects of samsung turbowrite on ssd's lifespan



## Abhinav Asna (Dec 7, 2015)

Does turbowrite reduce the lifespan of the ssd due to continuous write cycle on the cache zone.


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## micropage7 (Dec 7, 2015)

umm have you read this one?
http://www.tomshardware.com/answers/id-2140487/840-evo-ssd-sata-rapid.html


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## tabascosauz (Dec 7, 2015)

micropage7 said:


> umm have you read this one?
> http://www.tomshardware.com/answers/id-2140487/840-evo-ssd-sata-rapid.html



RAPID has nothing to do with TurboWrite.

@Abhinav Asna I don't see why TW should have a negative effect on endurance. There is a preset SLC zone in the 840 EVO, which I think goes up to 9GB for the 1TB. SLC has incredibly high endurance compared to MLC and TLC and I'm pretty sure that whatever you're writing to the disk isn't amplified, and in any case might be "reduced" by a portion of it going to SLC. It then all goes to the TLC when the drive is idle, so you end up writing the amount that you intend to the TLC. If it's the durability of the SLC you're worried about, I don't think there's any cause for concern.


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## Abhinav Asna (Dec 7, 2015)

micropage7 said:


> umm have you read this one?
> http://www.tomshardware.com/answers/id-2140487/840-evo-ssd-sata-rapid.html



Rapid mode uses ram. But turbowrite uses a cache or buffer in the ssd using the mlc as slc to increase performance.
The cache or buffer zone will be used regularly. Would this damage that zone.

http://www.samsung.com/hu/business-...14/01/Whitepaper-Samsung_SSD_TurboWrite-0.pdf


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## Ebo (Dec 7, 2015)

The way I see it, is dont even bother.
As I understand it, it will wear down the lifespan on your SSD by a little. What the gains, absolutely nothing since SSD drives has almost maxed out SATA III, and the speed gains you will get only shows up in artificial testruns, in normal life you wont even notice it.


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## tabascosauz (Dec 7, 2015)

Abhinav Asna said:


> Rapid mode uses ram. But turbowrite uses a cache or buffer in the ssd using the mlc as slc to increase performance.
> The cache or buffer zone will be used regularly. Would this damage that zone.
> 
> http://www.samsung.com/hu/business-...14/01/Whitepaper-Samsung_SSD_TurboWrite-0.pdf



Like I said, SLC has much higher endurance than your regular TLC. At the end of the day, you're still writing the same amount of data to the TLC (not any additional writes) and SLC is not going to fail before TLC.


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## Abhinav Asna (Dec 7, 2015)

tabascosauz said:


> Like I said, SLC has much higher endurance than your regular TLC. At the end of the day, you're still writing the same amount of data to the TLC (not any additional writes) and SLC is not going to fail before TLC.








The mlc simulates slc, but it is mlc the P\E cycles do not  change and unless buffer is full it will always be used.


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## tabascosauz (Dec 7, 2015)

Abhinav Asna said:


> The mlc simulates slc, but it is mlc the P\E cycles do not  change and unless buffer is full it will always be used.



So why did you ask if you just answered your own question? 

You seem pretty confident that TLC in SLC mode retains characteristics of TLC, so as far as we are concerned this question is answered.


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## Abhinav Asna (Dec 7, 2015)

tabascosauz said:


> So why did you ask if you just answered your own question?
> 
> You seem pretty confident that TLC in SLC mode retains characteristics of TLC, so as far as we are concerned this question is answered.



I meant to say that even though the mlc or tlc simulates slc their life will be considerably less than slc


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## RejZoR (Dec 8, 2015)

You can't "simulate" a NAND type. It's bullshit. What they are saying is that they are using deferred writing using DRAM cache. When drive receives write command it stores requested write data in a super fast DRAM cache (which on the outside to the user looks like write request was executed very quickly) and then slowly writes it down to actual NAND cells. It's what ALL SSD's except SandForce powered ones do. Writing has always been slower, they just use cache more conservaively on higher end drives because they are already fast as it is, but on cheap ones, it's more aggressive.


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## Abhinav Asna (Dec 8, 2015)

RejZoR said:


> You can't "simulate" a NAND type. It's bullshit. What they are saying is that they are using deferred writing using DRAM cache. When drive receives write command it stores requested write data in a super fast DRAM cache (which on the outside to the user looks like write request was executed very quickly) and then slowly writes it down to actual NAND cells. It's what ALL SSD's except SandForce powered ones do. Writing has always been slower, they just use cache more conservaively on higher end drives because they are already fast as it is, but on cheap ones, it's more aggressive.



I don't think dram and turbowrite buffer are the same as 120gb evo ssd have 256mb dram where as 3gb turbowrite buffer. The article I posted is samsung white paper on turbowrite which clearly states " To overcome this, the 840 EVO simulates faster SLC NAND on a portion of the drive to achieve much higher performance. "


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## R-T-B (Dec 8, 2015)

RejZoR said:


> You can't "simulate" a NAND type. It's bullshit. What they are saying is that they are using deferred writing using DRAM cache. When drive receives write command it stores requested write data in a super fast DRAM cache (which on the outside to the user looks like write request was executed very quickly) and then slowly writes it down to actual NAND cells. It's what ALL SSD's except SandForce powered ones do. Writing has always been slower, they just use cache more conservaively on higher end drives because they are already fast as it is, but on cheap ones, it's more aggressive.



Sure you can.  Just truncate the cell in the data write command.  Less data written = faster program times.  No effect on longevity as far as I'm aware, but since it's drawing from the entire TLC pool, it shouldn't make any difference as wear leveling will cover it.  It's not a fixed cell range and wont' always be the same cells.


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## Abhinav Asna (Dec 8, 2015)

R-T-B said:


> Sure you can.  Just truncate the cell in the data write command.  Less data written = faster program times.  No effect on longevity as far as I'm aware, but since it's drawing from the entire TLC pool, it shouldn't make any difference as wear leveling will cover it.  It's not a fixed cell range and wont' always be the same cells.



Thanks got my answer.
So the life will be same as other ssds using the same type of nand.


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## R-T-B (Dec 8, 2015)

Abhinav Asna said:


> Thanks got my answer.
> So the life will be same as other ssds using the same type of nand.



Pretty much.  Also since the 850's use 3d NAND on a lower process, the 3d TLC beats most planar MLC Nand in longevity.

So I see no need to worry.


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## RejZoR (Dec 8, 2015)

R-T-B said:


> Sure you can.  Just truncate the cell in the data write command.  Less data written = faster program times.  No effect on longevity as far as I'm aware, but since it's drawing from the entire TLC pool, it shouldn't make any difference as wear leveling will cover it.  It's not a fixed cell range and wont' always be the same cells.



So, basically they only use a single cell out of a triple cell to speed it up, but they spread it across more cells to get same usable capacity.


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## R-T-B (Dec 8, 2015)

RejZoR said:


> So, basically they only use a single cell out of a triple cell to speed it up, but they spread it across more cells to get same usable capacity.



Basically.  Samsung has a good write up on this somewhere, but yeah, essentially if they used 1GB of TLC as SLC (the exact amount they actual use escapes me) they only get a third of it back but it acts a faster sort of non volatile cache.


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