Longsys Foresee S500 SSD Review

A Closer Look

The Longsys S500 uses an industry standard 2.5-inch form factor case with a 7mm z-height for compatibility with newer notebooks that require a low-profile chassis.

The PCB you find inside is very small; it doesn't even take up half of the available space inside the case. We started noticing this trend several years ago. It allows manufacturers to minimize production costs to stay competitive as SSDs become commoditized. 

The final version of the SM2256 picked up the letter K at the end. We reached out to Silicon Motion for an explanation and were told that the K simply indicates a standard SM2256. This is a four-channel controller designed for mainstream users, so it is very power-efficient.

Longsys taps SK Hynix for its DDR3 buffer. The company also packages flash that it purchases from Micron, Toshiba and Samsung by the wafer. Again, the S500 we're testing today uses Toshiba's A19 TLC (19nm) NAND, with four packages on the PCB.

Data Type Comparison & SLC Cache

Silicon Motion controllers don't penalize high-entropy data with slow write speeds. Of course, it's important to buy the right SSD for your workload. You won't run into issues with this architecture if you specifically write a lot compressed data (multimedia, for example) like you would on some other drives. But that doesn't mean this SSD is your best choice for data-intensive tasks.

In fact, you'll run into performance issues when it comes time to write large files or lots of small ones to Longsys' S500. In the test above, we transferred 64KB blocks sequentially to see how long it'd take for write performance to drop to native TLC levels. Sixty-four kilobyte blocks allow us to see the drop-off better. Using 128KB blocks would nudge that boundary farther to the left, where it'd be hardly visible.

The two important take-aways from the graph are, first, that the SLC layer is quite small and, second, that the TLC's native 64KB sequential write performance is just under 90 MB/s. Small writes should be absorbed by the emulated SLC layer, but transfers of any substantial size will cut performance to half of what you can get from a modern mechanical disk.

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  • kalmquist
    The Silicon Motion's SM2256 based drives have the dubious distinction of being slower than what came before. I'm hoping that once companies other than Samsung get 3D NAND into mass production, we will see SSD's priced like the Longsys' Foresee S500, but with better performance.
  • ansar
    Bah. "S500" is the model name and not the size. :(
  • jtown80
    wonder how many backdoors they included...
  • Jeffs0418
    Quote:
    wonder how many backdoors they included...
    I was thinking the same thing. Just the possibility is a deal breaker for me.
    I just hope the (Korean) Samsung 850 EVO I purchased this year (Made in China)
    has no unwelcome firmware inside.
  • Jeffs0418
    The nice price is suspicious too...
  • photonboy
    The PRICE is right where it should be. It doesn't perform as well as slightly more expensive drives.
  • TbsToy
    Oh boy another cheap, substandard sata SSD with no visible support.
    Walt Prill
  • photonboy
    TbsToy,
    How do you know there is no support? Do you read Chinese?

    These exist in China, so I'm not sure why you would expect to easily find the support site.
  • TbsToy
    67821 said:
    TbsToy, How do you know there is no support? Do you read Chinese? These exist in China, so I'm not sure why you would expect to easily find the support site.


    Well, being in Los Angeles California USA and an English speaking American, I haven't ever felt the need to learn to read and speak Chinese just to be able to communicate with an unfindable Chinese support site for some substandard SSD that might not exist a month from now with a site ya can't even find. I can walk to Intel and with no time, and with no language or communication or warranty or shipment issues back and forth.. So I agree with you cuz ya might not have any usable support like the many SSD vendors have here. That shouldn't deter any potential buyers though, right, cuz it is cheap and ya wanna sell em, Right?
    Walt Prill
  • hannibal
    I just have to wonder, if most of the readers actually did read the article. This is not about Longsys, this is about controller, that will be the dominant controller in the next two years. Expect to see these in low price Samsung, Munchkin, Kingston etc ssd drives in near future.
  • 2Be_or_Not2Be
    "...transfers of any substantial size will cut performance to half of what you can get from a modern mechanical disk."

    A SSD that fails to beat a mechanical disk in every performance metric simply shouldn't be sold.
  • CRamseyer
    Your statement isn't accurate. This and other TLC SSDs are much faster at random access patterns.
  • epobirs
    Quote:
    Oh boy another cheap, substandard sata SSD with no visible support. Walt Prill


    The review makes it clear that end users are very unlikely to buy one of these from the OEM. You deal with a local vendor and their infrastructure. Do you speak Korean or read Hangul? No? Has that stopped you from buying Samsung products?
  • epobirs
    SATA SSDs are going to be a legacy market in just a few years. The cheapest devices will find a place in PCs at the low end before PCI-e connected SSDs take over the entire market. PC hardware and software designers are still coming to grips with how to apply the performance but the difference will become intolerable as the price gap narrows.
  • mapesdhs
    Chris, the Amazon Samsung 850 EVO link has the wrong price, it should be $90.

    Also, what's the point of the Service Time tests? They show no useful variation, at least not in terms of the comparison conveying anything that's relevant to making a purchasing decision.

    Lastly, why is the notebook battery life test graph using a non-zero origin? It means the visual impact of the graph is completely useless. I really wish toms writers would stop doing this, it's very bad practice. The whole point of a bar graph is to use the bars themselves as an immediate visual indication of variation, but non-zero origins make this impossible.

    Either way, once again, still no reason to get anything other than an 850 EVO atm, down to 114 UKP in the UK for the 500GB, below 60 for the 250GB. Amuses me to see people bidding more for other used inferior models on eBay. :D
  • hst101rox
    Quote:
    SATA SSDs are going to be a legacy market in just a few years. The cheapest devices will find a place in PCs at the low end before PCI-e connected SSDs take over the entire market. PC hardware and software designers are still coming to grips with how to apply the performance but the difference will become intolerable as the price gap narrows.

    The difference in performance in a desktop system will be minimal in most cases, except big file transfer jobs and the like. ~500MB/s is plenty! Your back to the CPU/ memory bottleneck for the most part.
    It'll be fun to see the 2TB Samsung SATA SSDs drop in price over time

    I don't see why anyone would buy this Longsys Foresee drive over a used 840 or 850 Evo on Ebay. mid range consumer SSDs don't really cost more than a low end SSD.
  • mapesdhs
    1748327 said:
    ~500MB/s is plenty! ...

    There's a long history in computing of people saying things like that which end up just being embarassing some years later. ;) Remember the old, "640K ought to be enough for anybody", by a certain Mr. Gates?

    When consumers start meddling with 4K video, suddenly "only" 500MB/sec will become annoying. It's not that far off. And the 450MB/sec I had this week when copying 140GB between two 500GB 850 EVOs definitely did not feel fast - oh how we get used to the quicker stuff so easily. Data expands to fill the space available, and patience shrinks to fit into the gaps. :D


    1748327 said:
    I don't see why anyone would buy this Longsys Foresee drive over a used 840 or 850 Evo on Ebay. ...

    I don't know why anyone is bothering with used EVOs on eBay atm when the cost of a new 250GB/500GB is so good. I've seen several UK listings these past couple of weeks where people have bought used SSDs for more than the cost of a new 850 EVO. That's just nuts.

    I bought another 850 EVO 250GB today, 58 UKP from Amazon. Really good price IMO, but it keeps dropping. The 500GB was at 113 a day or so ago.

    Ian.