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Comment by Reason077 | Hacker News Reader

The warranty on your EVO is just 150 TBW.

Yes, but endurance tests almost invariably show that the warranty ratings are extremely conservative. The 1TB 850 PRO (which uses exactly the same NAND chips as the 850 EVO, just a different controller) has been endurance tested to more than 7 Petabytes. See: http://packet.company/blog/

The older generations typically had better endurance, the newer generations are more dense (cheaper to produce) but less durable.

That was true when comparing MLC flash to TLC. But the 850 EVO and PRO use 3D V-NAND, which has significantly more endurance than previous-generation TLC. This seems to be confirmed by endurance tests.

your SSD should be OK for your for at least next 11 years

The warranty runs out after 5 years, anyway. But that does not mean it will suddenly stop working on that date!

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No, you're wrong. The 850 PRO uses MLC while the EVO uses TLC. But given that they're both constructed on Samsung's 3D-VNAND technology, their endurance is still much higher than the competitors out there.

> their endurance is still much higher

It's not "much" higher, actually, 3D MLC as implemented by Samsung is just "up to twice" better than the planar MLC given the same die area and capacity:

http://www.samsung.com/semiconductor/minisite/ssd/v-nand/tec...

"Samsung V-NAND provides up to twice the endurance of planar NAND."

But if the size of the cell drops, the number of P/E cycles drops. Samsung's endurance declarations are real and to be believed, they initially used bigger cells than some of their other chips (or competitors), but Samsung engineers know what they do, that "some tests" achieved "much more" can be either an accident or due to the errors in the test methodology (and I very much suspect the later, because it also allows the accidents to be taken as the "success"). At the time these SSDs appeared, Samsung declared twice less TBW than they do now, so now the declared endurance is surely not too pessimistic, but based on the real knowledge of what's inside.

Yes, you're right. But I don't expect an EVO to last for a full 7 PB of writes like the PRO did. But even if it lasts a fraction of that (say, approx 1 PB, which previous generation 840 EVO was able to achieve) then it's still 90 years of life at current usage levels! A (1 TB) 850 PRO would last over 600 years!

In all likelihood the drive will never get anywhere near any of these values - it'll be replaced with newer, better tech at some point. It may then get used for a backups or secondary storage, but in those scenarios the daily writes will drop enormously.

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