SSD Deathmatch: Crucial's M500 Vs. Samsung's 840 EVO

Inside Of Crucial's M500 SSD

Compared to the pentalobe and Torx screws that many drives employ, the four Phillips-head screws holding the M500's chassis together are easily removed.

The bottom of the enclosure is substantial, which gives the drive some heft. The thick casing also helps transfer some heat away from the SSD's internals. You don't want the flash inside getting too warm; that can throw off expected voltage levels, wreaking havoc on endurance (this is why thermal throttling is an important safeguard nowadays). Should the M500 get too hot, the controller will slow write performance above 70 degrees Celsius.

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With the PCB freed from its shell, the hardware is fair game for poking and prodding. Pictured above is the 480 GB drive, with eight packages per side. Each hosts two 128 Gb (16 GB) dies. The math there is pretty easy: every package adds 32 GB to this M500's capacity. Micron puts abbreviated codes on its NAND, but running it through the company's decoder gives us a traditional part number: MT29F256G08CECABH6.

Up top, we have Marvell's 88SS9187 BLK2 controller. As the successor to the '9174, which drove Crucial's m4, Plextor's M3s, Intel's SSD 510, and OCZ's Octane, the '9187 adds NAND redundancy features, queued TRIM commands, and even a little extra horsepower. It also supports up to 4 GB of DDR3 cache. Not that these drives need that much, but hey, maybe someday...

Crucial uses that controller with its custom firmware to implement RAIN (Micron's trade name for cross-die redundancy). Like some SandForce-based drives, this technology sets some NAND aside for parity. If one part of a die fails, the controller recovers and rebuilds the data stored in that location. It does sap some capacity (basically, one byte out of every 16), but the feature is a good trade-off in most situations. Some SandForce partners steered clear of the similar RAISE capability, opting instead to make that space accessible for a better price per gigabyte of capacity or use it to over-provision.

The M500's implementation of RAIN cannot recover from an entire die failing prematurely. Whole die failures do happen, unfortunately. But if just part craps out on you (say, one of the constituent planes that make up a die) the M500's RAIN feature should have your back.

This is the bank of itty-bitty capacitors that enables power loss protection (or PLP, if you please). This reliability-oriented value-add can be implemented a couple of different ways. The end goal is to protect information in the volatile write cache should your power go out suddenly. Once those bits hit the flash, they're safe. But they're vulnerable in the DDR3 DRAM and controller. PLP is purposed with safeguarding the entire data path.

Supercapacitors are basically big honkin' batteries, like a mini-UPS on the PCB. They've fallen out of favor over the past few years though, and many drives rely on a series of tantalum caps to keep data flowing when power to the SSD is interrupted. Crucial goes with a slightly different approach on the M500, though. Armed with a series of small caps, the controller flushes most of what's in the cache, while using "NAND tricks" to make up any deficit. At any given time, there's only 1 to 4 MB of user data in the DRAM, so it's not like the hardware is trying to write the Great American Novel in a handful of microseconds.

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29 comments
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  • Someone Somewhere
    I think you mixed up the axis on the read vs write delay graph. It doesn't agree with the individual ones after, or the writeup.
    2
  • Someone Somewhere
    Even 3bpc SSDs should last you a good ten years...

    The SSD 840 is rated for 1000 P/E cycles, though it's been seen doing more like ~3000. At 10GB/day, a 240GB would last for 24,000 days, or about 766 years, and that's using the 1K figure.

    You're free to waste money if you want, but SLC now has little place outside write-heavy DB storage.

    EDIT: Screwed up by an order of magnitude.
    8
  • cryan
    Anonymous said:
    I think you mixed up the axis on the read vs write delay graph. It doesn't agree with the individual ones after, or the writeup.


    You are totally correct! You win a gold star, because I didn't even notice. Thanks for catching it, and it should be fixed now.

    Regards,
    Christopher Ryan
    6
  • cryan
    Anonymous said:
    I would only buy SSD that uses SLC memory. I dont wan't to buy new drive every year or so.


    Not only are consumer workloads completely gentle on SSDs, but modern controllers are super awesome at expanding NAND longevity. I was able to burn through 3000+ PE cycles on the Samsung 840 last year, and it only is rated at 1,000 PE cycles or so. You'd have to put almost 1 TB a day on a 120 GB Samsung 840 TLC to kill it in a year, assuming it didn't die from something else first.

    Regards,
    Christopher Ryan
    2
  • Someone Somewhere
    I'd like to see some sources on that - for starters, I don't think the 840 has been out for a year, and it was the first to commercialize 3bpc NAND.

    You may be thinking of the controller failures some of the Sandforce drives had, which are completely unrelated to the type of NAND used.
    8
  • mironso
    Well, I must agree with Someone Somewhere. I would also like to see sources for this statement: "Yes, in theory they last 10 years, in practise they last a year or so.".
    I would like to see, can TH use SSD put this 10GB/day and see for how long it will work.
    After this I read this article, I think that Crucial's M500 hit the jackpot. Will see Samsung's response. And that's very good for end consumer.
    2
  • edlivian
    It was sad that they did not include the samsung 830 128gb and crucial m4 128gb in the results, those were the most popular ssd last year.
    -1
  • Someone Somewhere
    You can also find tens of thousands of people not complaining about their SSD failing. It's called selection bias.

    Show me a report with a reasonable sample size (more than a couple of dozen drives) that says they have >50% annual failures.

    A couple of years ago Tom's posted this: http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html

    The majority of failures were firmware-caused by early Sandforce drives. That's gone now.

    EDIT: Missed your post. First off, that's a perfect example of self-selection. Secondly, those who buy multiple SSDs will appear to have n times the actual failure rate, because if any fail they all appear to fail. Thirdly, that has nothing to do with whether or not it is a 1bpc or 3 bpc SSD - that's what you started off with.

    Quote:
    This doesn't fix the problem of audience self-selection
    9
  • Someone Somewhere
    You were however trying to stop other people buying them...

    Sounds a bit like a sore loser argument, unfortunately.

    SSDs aren't perfect, but they generally do live long enough to not be a problem. Most of the failures have been overcome by now too.

    Just realised there's an error in my original post - off by a factor of ten. Should have been 66 years.
    7
  • warmon6
    Anonymous said:
    I am not talking about Samsung SSD-s, I am talking about SSDs in general. And I am not going to provide any sources because SSD fail all the time after a year or so. That is the raility. You can find, on the internet, people complaining abouth their SSD failing. There are a lot of them...
    Also, SLC based SSD-s are usually "enterprise", so they are designed for reliability and not performance, and they don't use some bollocks, overclocked to the point of failure, controllers. And have better optimised firmware...


    Tell that to all the people on this forum still running intel X-25M that launched all the way back in 2008 and my Samsung 830 that's been working just fine for over a year.......

    See what you're paying attention too is the loudest group of ssd owners. The owners that have failed ssd's.

    See it's the classic "if someone has a problem, there going to be the one that you hear and the quiet group, isn't having the problem" issue.

    Those that dont have issues (such as myself) dont mention about our ssds and is probably complaining about something else that has failed.
    4
  • Someone Somewhere
    Quote:
    Yes, in theory they last 10 years, in practise they last a year or so.

    Quote:
    because SSD fail all the time after a year or so.


    Those don't seem like opinions to me. It's customary to include some form of leeway in the sentence, like 'IMHO', 'often', or 'I've heard' etc.
    6
  • InvalidError
    Anonymous said:
    At 10GB/day, a 240GB would last for 24,000 days, or about 766 years, and that's using the 1K figure.

    Assuming the system has more than enough RAM to avoid needing any significant amount of swapping. If someone with 4GB RAM uses a 16GB swapfile to avoid upgrading to the 8-16GB RAM he really should have, he could end up writing over 1GB/minute.

    I have ended up over-crowding my RAM many times in the past and it has a tendency to make my computers practically unusable when using mechanical HDDs at which point I had to spread my programs and swapfile across multiple HDDs to reduce the IO load on individual drives. I imagine this would burn through SSDs fairly quickly.
    5
  • jryder
    Anonymous said:
    I am not talking about Samsung SSD-s, I am talking about SSDs in general. And I am not going to provide any sources because SSD fail all the time after a year or so. That is the raility. You can find, on the internet, people complaining abouth their SSD failing. There are a lot of them...
    Also, SLC based SSD-s are usually "enterprise", so they are designed for reliability and not performance, and they don't use some bollocks, overclocked to the point of failure, controllers. And have better optimised firmware...


    Anecdotal evidence is pretty useless. People with very good or very bad experiences tend to write reviews. People generally don't write reviews for random pieces of hardware that just work as expected. Provide citations with statistics to support your statements if you want anyone to take them seriously.
    4
  • colson79
    Anonymous said:
    Are you bloody shitting me?! What am I, a mechanical drive lobby, spreading anti-SSD propaganda???

    I will not be replying to this topic any more. All I wanted to do is say my opinion, but there had to be some smartass telling me that I don't have the right to do it. Noooo, I have to source it. This is my oppinion, get over it.


    You are entitled to your opinion but you are making bold statements without any facts. A lot of people use forums like these to research products they are thinking about buying and you are spreading misinformation about SSD's without and evidence for your statements. I personally have 4 computers with SSD's in them that are over 2 years old and I haven't had a single issue or failure. It really pisses me off when people start spreading inaccurate statements that may turn away a potential user of a SSD. Out of all the PC upgrades I have done in the past 12 years the SSD has been the best most noticeable improvement I have done.
    8
  • Onus
    Disagreement among techies is inevitable, but please watch language.


    Just to stick an oar into the reliability issue, my Samsung 830 has run reliably for over two years now. The only SSDs I had fail in use were a couple of Sandforce drives, but their replacements have thus far been reliable. I think InvalidError has a good point about RAM though; I tend to use at least 8GB, which probably cuts down swapping quite a bit. I also prefer to close programs completely rather than have a lot of windows open, which would also reduce swapping. With a SSD, they re-open pretty quickly anyway.
    4
  • dalethepcman
    Wow, nice 180 there anti global. I have used many SSD's in both enterprise and personal use, and their reliability has been on par with enterprise level HDD's. We currently use a mix of Samsung 830/840's and crucial m400's for SSD's and with the increased capacity and incredible price drops, the m500 would be an easy drop in upgrade.
    0
  • bullwinkel
    I've purchased 3 different SSDs over the last 2 years. My first purchase was an Agility 3 64gb that I used as a boot drive for my machine that I just build. About 6 months later I purchased an M4 128gb to be used for running select applications. About 6 months after the M4 purchase, I bought an 840 500gb. I moved my OS to the M4, applications to the 840 and gave my Agility 3 to my brother to be used in his machine as a boot drive. Never had a single problem with any of them. SSDs are fantastic. Pretty soon, when the price of the TB drives come further, the only mechanical storage I'll be using is for backups.
    2
  • rrbronstein
    Anonymous said:
    Are you bloody shitting me?! What am I, a mechanical drive lobby, spreading anti-SSD propaganda???

    I will not be replying to this topic any more. All I wanted to do is say my opinion, but there had to be some smartass telling me that I don't have the right to do it. Noooo, I have to source it. This is my oppinion, get over it.


    LOL, when you come onto an article about SSD's and say nonsense like you did, you have to expect to get hate buddy. MLC/TLC is very viable and lasts much longer than a year kid, some drives do fail, and if they do you get your replacement. Other peoples drives are not lemons and last a normal lifetime, common sense bro.
    3
  • anything4this
    As stated, it was mostly sandforce drives that failed. Have bought 7 SSD's (Crucial, Samsung, Plextor) and all are working perfectly awesome (rather than just fine :P )
    2
  • ethanolson
    My wife is running an X-25M G2 and I just got an M500. The X-25M gave her at least two more years out of her system and the M500... holy cow is this thing awesome! Everything feels like it should.

    Oh, I highly recommend getting the drive migration kit from Crucial for ~$20. It makes like much easier. It's a USB 3.0 SATA drive connector for your M500. Then just boot the supplied CD and run it in auto mode to copy over your drive exactly and make any sizing adjustments needed to the partitions to get it to fit. It works very nicely.
    3