Samsung 850 Pro: TLC or MLC?

omega3

Senior member
Feb 19, 2015
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I'm a bit confused after reading this Anandtech review. It says "Even today, the SSD 840 and its successor, the 840 EVO, are still the only TLC NAND based SSDs shipping in high volume. Now, two years later, Samsung is doing it again with the introduction of the SSD 850 Pro, the world's first consumer SSD with 3D NAND."

First I thought the non-Evo 840 had the better MLC, not TLC..

But then about the 850 Pro.. does this use 3D TLC or MLC.. and if it is indeed 3D MLC, is it just as durable as "regular" MLC..

I mean, by putting things closer together (3D), doens't that allow for more memory leakage, even if it is MLC. For me durability is the most important.

Also strange that the 840 Pro is still more expensive then the newer 850 Pro.
 
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Elixer

Lifer
May 7, 2002
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850 EVO uses 3-Bit MLC 3D-VNAND.
850 Pro contains 2-Bit MLC 3D-VNAND.
 

SSBrain

Member
Nov 16, 2012
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I'm pretty sure the 850 Evo does not use MLC but TLC, no :confused:

3-bit MLC means "TLC".
2-bit MLC is what is popularly defined as "MLC".

I wonder why they just aren't called 2LC, 3LC, 4LC and so on, that would be clearer in my opinion :hmm:
 

AlienTech

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Apr 29, 2015
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They only make SLC nand.. In fact all nand chips can work in any mode you want even QLC.. The only question is reliability after a few uses. There are many SSD's that use part of the area as an SLC cache buffer before moving the data to MLC or TLC areas. Since the voltage levels in the cells are like 18V, after a while the cells cannot hold the proper charges over longer periods of time. SLC which is used in like BIOS roms and such are able to work for decades. I bet in another decade we will see chips holding 10 bits or more. The controllers would be so advanced that they would work like DRAM which refreshes data many times a second. They are getting pretty advanced already where they can find out how good a particular cell in the chip is and program it accordingly. I am surprised it is taking this long for TLC to be used by everyone.
 

Spanners

Senior member
Mar 16, 2014
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EVO = TLC Garbage NAND
PRO = MLC NAND FTW

It's a different type of NAND with it's own pros and cons. I know you had a bad experience because you purchased some 840 EVOs but painting TLC as a technology "Garbage" because of a bad implementation is just wrong imho. Obviously it's the cost conscious solution and that comes with downsides but it's not garbage.

There have been no reports of any issues with the 850 EVO (which has been out for long enough now I think) and you can bet people were on the lookout for any issues if they emerged.
 
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omega3

Senior member
Feb 19, 2015
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It's a different type of NAND with it's own pros and cons. I know you had a bad experience because you purchased some 840 EVOs but painting TLC as a technology "Garbage" because of a bad implementation is just wrong imho. Obviously it's the cost conscious solution and that comes with downsides but it's not garbage.

There have been no reports of any issues with the 850 EVO (which has been out for long enough now I think) and you can bet people were on the lookout for any issues if they emerged.

We all know MLC nand is the best but TLC is cheaper.
Micron claims 50% of the ssd will be TLC nand in 2016.

http://www.kitguru.net/components/m...f-our-ssds-will-be-based-on-tlc-nand-in-2016/

OK, but both 850 EVO and PRO use TLC or MLC in this "3D-VNAND" configuration, so does it still hold true that the TLC used in it will be "worse" and how exactly would that be?

Which advantages are there realy to the 850 Pro really since it obviously costs more money?
 

john3850

Golden Member
Oct 19, 2002
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The problem was not with the 3D-VNAND it was the 3-bit TLC nand that had related problems holding the needed voltage for a given time on the 840evo.
 

omega3

Senior member
Feb 19, 2015
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The problem was not with the 3D-VNAND it was the 3-bit TLC nand that had related problems holding the needed voltage for a given time on the 840evo.
So does it make sense or not that TLC used in this new 3D-VNAND context has no chance of getting the same performance degradation problems that still plague the 840 Evo?

If so, what exactly are the real benifits of getting the 850 Pro instead of the 850 Evo which costs less?
 

omega3

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Feb 19, 2015
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coercitiv

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Jan 24, 2014
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Which advantages are there realy to the 850 Pro really since it obviously costs more money?
Endurance & Performance consistency - it will withstand more than double raw writes compared to 850 EVO and will also behave better under very heavy loads, with little free space to work with.

That being said, none of these advantages apply to typical consumer loads.
 
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redzo

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Nov 21, 2007
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850 evo suits the needs of 99% of client PC's. It's cheaper, faster than the old 840 evo and it should be more durable due to the nature of 3d nand; all mentioned above.

Except for the read performance degradation bug, I've never had any issues with my 840 evo. I'm actually quite pleased with the 840 evo overall.

I'm usually loyal to the brand that doesn't brake. Reliability is what I cherish the most out of a product. But samsung should watch out: if it brakes immediately after the warranty period or in its last year of warranted service(and the rma is bad), I'm gonna bitch about it all over the forums.