If you are a forum active or a recent buyer of Kingston SSDNow V300 SSD, there is a chance that you're aware of its performance issues. In short, users have been reporting lower performance (up to 300MB/s difference in AS-SSD sequential read speed) of drives with 506 firmware pre-installed, which is the version retailers currently sell. I've received numerous emails regarding this issue from readers looking for answers, and now I finally have them.

Like many SSD OEMs, Kingston buys its NAND in wafers and does its own validation and packaging. As a result figuring out the original manufacturer is not possible without the help of Kingston because there are no public data sheets or part number decoders to be found. I've never been a big fan of OEM-packaged NAND because OEMs tend to be more tight-lipped about the specifics of the NAND and it's easier to silently switch suppliers, although I do see the economical reasons (NAND is cheaper to buy in wafers).

So far there's not been much harm from this but I've been fairly certain that someone would sooner or later play dirty and use NAND packaging as a way to mask inferior NAND. Unfortunately that day has come, and as you can guess the OEM in question is Kingston and the product is their mainstream V300 SSD.

The first generation V300 (which was sampled to media) used Toshiba's 19nm Toggle-Mode 2.0 NAND but some time ago Kingston silently switched to Micron's 20nm asynchronous NAND. The difference between the two is that the Toggle-Mode 2.0 interface in the Toshiba NAND is good for up to 200MB/s, whereas the asynchronous interface is usually good for only ~50MB/s. The reason I say usually is that Kingston wasn't willing to go into details about the speed of the asynchronous NAND they use and the ONFI spec doesn't list maximum bandwidth for the single data rate (i.e. asynchronous) NAND. However, even though we lack the specifics of the asynchronous NAND, it's certain that we are dealing with slower NAND here and Kingston admitted that the Micron NAND isn't capable of the same performance as the older Toshiba NAND.

Comparison of Kingston V300 Revisions
Revision Original (no longer available) New (currently available)
Pre-Istalled Firmware 505A 506A / 521A
NAND Toshiba 19nm Toggle-Mode 2.0 Micron 20nm asynchronous
NAND Interface Bandwidth 200MB/s ~ 50MB/s (?)
AS-SSD Incompressible Sequential Read ~ 475MB/s ~ 170MB/s
AS-SSD Incompressible Sequential Write ~ 150MB/s ~ 85MB/s
AS-SSD Incompressible 4K Read ~ 20MB/s ~ 15MB/s
AS-SSD Incompressible 4K Write ~ 110MB/s ~ 65MB/s

* AS-SSD performance data based on screenshots provided by a reader

Update: Apparently there is also a newer revision with 521A firmware floating around that utilizes the slower asynchronous NAND.

Update 2: NordicHardware has tested both the 505A and 521A versions and their testing confirms the decrease in performance. What is even more alarming is that based on their tests, the performance decrease is not limited to just incompressible performance but there is a noticeable difference in real world trace-based tests as well. The article itself is in Swedish but the graphs should be easy to understand and you can always use Google Translate

I have to say I'm disappointed. I thought the industry had already learned from its mistakes and that a switch in NAND supplier shouldn't be done silently (remember the hullabaloo OCZ caused when they silently switched from 34nm to 25nm NAND in Vertex 2?). Kingston assured me that this wasn't an intentional attempt to screw customers but a strategy decision made in order to stay within the bill of materials. Kingston was aware that they would have to switch suppliers at some point and in fact they are now looking for yet another supplier (likely Toshiba again). Frankly, I don't see the supplier change as an issue; the problem is that it was done without any notice and there's no public indication of what sort of NAND you'll get.

Kingston did say that they considered updating the name to V305 or similar to distinguish the two but in the end decided against that. In our talks we agreed that it wasn't a very good decision. It's not fair to sample media with one thing and then later start selling something else. Not everyone reads reviews but the buyers who do expect a certain level of performance and it's obvious that they will feel cheated if their unit performs significantly worse. I hope this is just a one-time occasion because that's perhaps excusable, but if this becomes a habit things will start to be fishy. Ultimately, the V300 wasn't a particularly fast SF-2281 SSD when it launched, but with the NAND update it's become quite a bit slower than other alternatives.

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  • axiommods - Tuesday, March 4, 2014 - link

    The second this story broke the kingston v300 drives were on sale for $59.99 on Amazon and every other outlet. I got an inscreen ad on youtube.com showing me the drive advertised for dirt cheap on Amazon. It was not a targeted ad either. I never searched for SSD drives. The only thing I did was read this article. Unless , youtube ad generators searched my browser history. That could be it. But I didnt search for kingston V300 SSD. Either way, since they're outed....expect more price drops
  • lokhor - Tuesday, March 4, 2014 - link

    I have one of these drives and was pretty shocked to hear about. Thank god mine has the 505 firmware. Never going to buy Kingston again though.
  • HisDivineOrder - Tuesday, March 4, 2014 - link

    They knew that if they changed the model number and offered subpar performance, any gain they got from using lower cost NAND would have been offset by the pricing they'd have had to use.

    This way, they made tons of money off saps before they figured out what had happened.

    Kingston just joined OCZ on my "No way, no how" list.

  • psychobriggsy - Tuesday, March 4, 2014 - link

    Ugh, I bought one of these just a week ago with the express aim of it actually speeding up my system over the spinning HD it previously had. Shame I've chucked the packaging away. I'll have to check the firmware to see which one I have.

    Changing the performance characteristics of a product so drastically with a revision is just not on, it's really bad practice, it's dishonest and it is deceptive trading.

    Maybe they've only done this in territories with poor customer protections in place. Would be interesting if people complained and they had to replace all the affected products. Retailers will be unhappy too - they didn't know Kingston have shat all over their own products, and now they'll be getting complaints and returns as awareness of the issue grows.
  • jabber - Tuesday, March 4, 2014 - link

    If they keep dropping in price I'll buy them. I always feel its not the raw MBps that counts but the access times. As long as they are still an order of magnitude higher in seek than a HDD thats fine with me. Plus they are cheap! More than handy for fast testing drives and swapouts.
  • Storage Gal - Wednesday, March 5, 2014 - link

    Is there a reason that the benchmarking was done with incompressable data? My understanding is that "compression" is a main feature of the Sandforce Controller used on this SSD? Does using compressable data change the performance numbers?
  • Paris Kitty - Wednesday, March 5, 2014 - link

    Thank you for publishing this valuable information.
    I knew absolutely nothing about this NAND scandal and purchased Kingston SV300 at Amazon France last November. Luckily, the version I received (520A) was made with Toshiba NAND.
    I gathered more information on net and found out that those shipped with Firmware 505/520 are OK, but 506/521 are not. I checked the product page at Amazon France but there are only a few complains from buyers about speed of the product without much explanation. I posted the information I found to caution other Amazon buyers.
    What Kingston did may not be illegal but ethically very incorrect. I took a vow never to touch their product again, especially after I read this comment at Amazon USA: http://www.amazon.com/Kingston-Digital-Adapter-SV3...
    Kingston hid this fact by using solvent on the original labeling of the memory chips, then printed their own logo on top. Kingston does not manufacture any memory themselves. When SSD was shipped out for review it used quality Toshiba 19nm NAND but Kingston used solvent on chips labels and printed their own. This was odd, but the reason for it soon became obvious. After only a few months they switched to inferior quality chips with the same Kingston label. <unquote>
  • reality4321 - Thursday, March 6, 2014 - link

    The only question people should be asking is 'does the drive perform to published specifications'?? That is all that matters. So, you got free cheese with your burger for a while...well, that cheese went away but its still the burger , as described.
    People are so fast to trash companies without using logic. If it performs to spec, that is all you should get.
  • Bob Todd - Thursday, March 6, 2014 - link

    Um...no, just no. That's like saying that if Intel sampled 4770K processors, then silently replaced the cores with a version that could score the same in 1 benchmark but delivered 1/2 to 1/3 the performance in a bunch of other real world scenarios nobody should care. The asynchronous NAND versions of these drives have far lower sequential write performance for non-compressible data than a friggin' mechanical hard drive. The write speed is on par with an external 5400rpm mechanical drive over USB3. Kingston is taking this one on the chin, and they deserve every second of it. They can switch NAND all they want, just do the right thing and change the product name/SKU.
  • Korsi - Friday, March 14, 2014 - link

    480GB 420ABBFO made in Taiwan okey.
    Slow 4k write but test wasn't even close to optimal. It is system disk win 8.1 and a lot of programs running, including utorrent.
    atm it looks like the problem is with 120 and 240GB v300 drives.

    Kingston is making it's last grasp for money and trying to unload their SSD inventory and then file their SSD line for bankruptcy. Can't make any other sense on the fact that they are knowingly lying to their customers and thus losing a lot of future customers.
    It is easy to break the companys imago but it takes years to build it back.

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