Samsung Returns To 2D, Releases 250GB 750 EVO For $75

Vigile writes: Even with Samsung pushing forward into 3D NAND with 32-layer technologies used in SSDs like the 850 Pro and the recently released M.2 PCIe NVMe 950 Pro, there is still plenty of traditional 2D planar memory being fabbed on production lines. To utilize that inventory, Samsung is shifting its low-capacity SSDs back to it, announcing the 750 EVO drives today available in 120GB and 250GB capacities. Though based largely on the very popular, but sometimes troubled, 840 EVO specs, the new drives are faster and start with some impressively low prices. The starting MSRP for the 250GB 750 EVO will be just $75.

Comments

and the crowd

[Anonymous Coward]

went mild

What were the problems with 840s?

[swb]

I've installed over a dozen of these without any problems, including as an upgrade in an old Dell laptop that got 2+ years of very mobile use and still works fine AFAICT.

Re:What were the problems with 840s?

[drinkypoo]

ISTR they had weird TRIM behavior and the Linux blacklist hadn't been updated for them or something. Now it has and they'll be fine, even if they do TRIM weirdly. ... yep, I checked the link from the summary, and that's the story

Re:What were the problems with 840s?

[AmiMoJo]

Because they were storing 3 bits per cell, that means 8 possible voltage levels. The voltage tends to vary over time if the data isn't touched. The SSD would read a block of cells, notice that the voltage levels were a bit off and re-calibrate, and then do another read. This result in greatly reduced read performance (200MB/sec down from near 500MB/sec).

They issued a firmware update that did something to alleviate the problem, and added background scans to do the re-calibration when the drive was idle which eliminated the problem completely on most systems.

The newer drives seem to be totally immune.

Re:What were the problems with 840s?

[Solandri]

A flash cell is basically a capacitor which holds an electrical charge at a certain voltage. The voltage level tells you the data that's stored in the cell. In the simplest case (1 bit), a 0 is no voltage, a 1 is high voltage. MLC stores 2 bits (4 voltage levels), TLC stores 3 bits (8 voltage levels). With increasing number of bits, the voltage difference between different levels becomes smaller.

The problem is, that charge slowly leaks out of the cell. As they reduced the lithography and the cells got smaller, the surface area to volume ratio grew. The stored charge was proportional to the volume, while the rate of leakage was proportional to the surface area. So basically shrinking the lithography meant the cells leaked their charge faster. All this came to a head in the 840 EVO series. The rate of leakage was high enough and the voltage difference between the values on TLC were small enough that the voltage of the cell dropped out of spec within a few months. And the SSD began having trouble reading the data back reliably from the cell.

Fortunately Samsung built in a ton of error correction, so when this happened the data wasn't actually lost. The SSD tried reading the cell over and over again until it randomly got the correct CRC value and knew it had a clean read. Unfortunately, all those re-reads took a lot of time, and the performance of the SSD tanked. Samsung's fix (pretty much the only fix possible) was to re-write cells which had old data in them to give them a fresh charge, basically resetting the countdown before the data became corrupt again.

With 3D NAND, because the cells are also stacked vertically, it wasn't as important to make the cells so small. So Samsung went from 19nm lithography in the 840 EVO, to 40nm lithography in the 850 EVO. No leakage problem at 40nm (at least not for several decades, if that). Likewise, the 840 Pro used MLC (the EVO used TLC). So it had twice the margin of safety on the voltage values before data corruption, and thus didn't suffer this problem. Now that they're returning to 2D NAND for this new line of drives, people are rightly asking if this voltage leakage is going to become a problem again.

Re:What were the problems with 840s?

[labnet]

I had an 840 (Dells OEM version), in my Nice XPS15 system which became unusable after about 8months. Using the rewrite tricks didn't fix it. Had to replace it with an 850.

Re:What were the problems with 840s?

[gweihir]

This only hit you with bleeding-edge kernels. Distro-kernels were fine, I think. Still shows that SSD is not a completely mature technology at this time.

Re:What were the problems with 840s?

[drinkypoo]

This only hit you with bleeding-edge kernels. Distro-kernels were fine, I think. Still shows that SSD is not a completely mature technology at this time.

What is? Nothing that's getting better, which is everything that's not getting worse :)

Re:What were the problems with 840s?

[gweihir]

Traditional HDDs are a mature technology. The maximum reliability they have at consumer-prices is not likely to get any better than it is now. Their reliability varies between models and over time, but basically it is something like 1...10% failure (if treated well) per year. SSDs will hopefully get much better numbers eventually, CPU-like reliability would be nice.

Re:What were the problems with 840s?

[drinkypoo]

Traditional HDDs are a mature technology.

You say that, but for example that backblaze article recently (or the others like it) show that there's quite a bit of variability because they continually change technologies to some degree while chasing higher densities.

Re:What were the problems with 840s?

[gweihir]

Variability does not indicate the technology is immature. It just says that manufacturers are juggling for better trade-offs between cost and reliability and there are new designs (that are based on older ones) regularly. Well, sure, no computer tech is strictly mature, not even, say, Cherry switches. If you really go for it, not even paper is mature, despite the Human race having been making it for about 2000 years. So with a very strict definition of maturity, HDDs are certainly not mature, but it does not make much sense to use that definition.

But my point was that SSDs have surprising failure modes and causes of failure, while HDDs basically do not have them these days. Again, mostly. A Helium-filled drive will have some novel failure-modes linked to loss of Helium, for example.

The 850 series already offered this

[NotDrWho]

The Samsung 850 series has been offering 30-cents-per-GB SSD drives for some time now (going up to 1 TB).

They are still 3d

[Billly Gates]

They are keeping them for the higher margin more enterprise and gamer/enthusiats market.

I only buy pro's and I own a 3d 850 pro for my main rig. THey are well worth the extra $25 as the previous evo's all experience slowdowns and lockups. I heard a firmware update fixed them but we got burned here.

But 3d is expensive and the cost to fabricate goes down. This is good news for the consumer market as even a consumer grade drive is so many miles ahead of a mechanical disk as long as they do not slow down or break.

Not exactly a steal.

[DidgetMaster]

I bought a 250 GB 850 EVO last year for $75 at Amazon. Unless you will be able to find these $75 MSRP drives on sale for $50....

Re:Not exactly a steal.

[BenJeremy]

I think that will be the case... these drives will be available, more often than not, for less than $50, perhaps as low as $35.

Samsung is great for driving down market prices.

Re:no thanks

[Billly Gates]

I prefer my SSD to last more than 6 months before presenting errors and issues. I know, I'm crazy like that.

I had great luck with their pro drives. My Samsung 840 pro raid 0 has been up for several years now for my home labs and high performance games :-) No issues at all as the pro series with the 3d technology is only $35 more than the evo's and worth it as they go through extra QA as they are enterprise grade as well if you are worried about reliability.

  I bought some value sansdisk ones a few years ago and one started getting corruption. I guess you get what you pay for. But compared to 2009 with the sh*tty sandforce controllers the reliability is mountains better today.

$75 for 250GB is no longer "cheap"

[FlyHelicopters]

Yes, I am aware that is the "suggested list price", and that actual selling prices will likely be lower...

However, you can already buy the very good, very reliable 240GB Crucial BX200 drive for $65 at Amazon, and there are other choices for $60 and lower if price is everything.

http://amzn.to/20ZdOwy

I have several of the BX200 drives in basic machines around the office, they work just fine, no hassles or issues.

Re:$75 for 250GB is no longer "cheap"

[Junta]

And the MSRP for that device is $85 dollars. So this is 5% more storage at 12% lower price, comparing apples to apples.

Remember, in this market the MSRP is a vague upper limit rather than a particularly precise indicator of real pricing.

Re:$75 for 250GB is no longer "cheap"

[FlyHelicopters]

That is true... And if this new 750 EVO ends up being $50 on the street, I'll probably buy 5 of them. :)

I was simply making the point that $75 is no longer "cheap" for this size, but yes, you are correct.

Re:$75 for 250GB is no longer "cheap"

[Junta]

True enough. People who don't look get shocked that you can get 512 now for like $115 or so. Of course hard drives that are way bigger are less, but for 250 GB or less, there's no reason for hard drives anymore (both scale down to ~50 baseline price per device, so getting tiny hard drives won't get you the price/GB benefit). Before too long at the rate things have been going, 512 GB will be the clip level where it makes zero sense.

Re:$75 for 250GB is no longer "cheap"

[FlyHelicopters]

All true...

Depending on your use case, I'd argue that we're more or less there.

While 1TB SSDs are still "pricey" at $250-300, the 500GB level is really nice these days.

A 1TB HDD is about $50, a 500GB SSD is about $120. Yes, that is more for less space, but how often will you use your computer? How much time will you spend waiting for the computer vs. the computer waiting for you?

It isn't right for everyone, but I'd submit that in a $500-1,000 computer, a $70 price difference is pretty minor and most people don't actually need 1TB anyway.

I see a lot of 1TB drives with less than 200GB of data on them.

One thing that our shop does is a lot of 250GB SSD installs, we make the existing 1TB HDD the "data" drive and clone Windows to the SSD.

Re:$75 for 250GB is no longer "cheap"

[Wolfrider]

--May I ask what cloning software you use / recommend for HD -> SSD Windows 7 / Win10?

Re:$75 for 250GB is no longer "cheap"

[FlyHelicopters]

Most SSDs include free cloning software.

The Samsung and Crucial drives that I usually use, provide such software for free. I have yet to need anything else personally.

Re:no thanks

[mprindle]

According the article the early problems with the 840 line that was fixed will have the corrections carried to the 750 line.

Re:no thanks

[0100010001010011]

All of my Samsung SSDs have lasted longer than my Seagate paperweights.

Market Forces

[Virtucon]

Samsung moves to maintain market share. #Whodathunkit

Re:no thanks

[Anonymous Coward]

According the article the early problems with the 840 line that was worked around will have the corrections carried to the 750 line.

Compatibility with 3D

[marciot]

This is great for digital artists that work in 2D, but what about 3D models? Will this drive squash the files down to 2D?

The big question

[Dunbal]

Does it spy on you like other Samsung products?

Re:no thanks

[gweihir]

Indeed. And they did actually fix the problems, at least for my 750GB Evo. It was a bit of a pain though, so now I am only buying the Pro models. Zero problems with them so far, quite unlike some other manufacturers I could name. I even have several completely dead SSDs.

Re: no thanks

[eWarz]

My 840 evo has never given me any issues. Bought it at launch.