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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  • Jeffrey Bosboom - Monday, March 3, 2014 - link

    So, are you going to update your review with a disclaimer explaining that what's being sold now is different from what you tested?
  • sausagefingers - Monday, March 3, 2014 - link

    I think updating the original article with a link to this one is a good plan.
  • Kristian Vättö - Tuesday, March 4, 2014 - link

  • Communism - Monday, March 3, 2014 - link

    Never Purchase an SSD that isn't from a NAND manufacturer.

    Never Purchase DRAM that isn't from a DRAM manufacturer.
  • Bob Todd - Monday, March 3, 2014 - link

    Your RAM all has SK Hynix, Micron/Elpida, or Samsung on the packaging?
  • DanNeely - Monday, March 3, 2014 - link

    I assume he's using all Crucial ram (Crucial is Micron's house brand).
  • Bob Todd - Monday, March 3, 2014 - link

    Thanks for posting this. I purchased one 120GB model on sale recently for $70 (that went on sale again for $65). I went back and read old reviews before purchasing, including the one from Anandtech, and naturally it looked like a good drive for that price. Time to bug customer support for a return while it is still unopened. The only other Kingston SSDs I have are a trio of HyperX 3K drives for family members, and so far those had been solid (I only paid $65 on Black Friday two years ago). The good experience with those drives actually cemented the V300 purchase, and now Kingston is off the list indefinitely.
  • Bob Todd - Thursday, March 6, 2014 - link

    Props to Newegg for letting me return this junker. Just a note for anyone who has bought these on sale recently and hasn't opened the packaging, the firmware is listed on the bottom right corner of the Kingston sticker on the face of the drive. E.g. "521ABBF0" has the 521 firmware. So it's easy to tell which version you got without potentially killing your ability to return the thing.
  • alaba - Tuesday, March 4, 2014 - link

    I wonder if we're going to see another OEM go out of business. I'm sure even if they start producing the best SSDs out there, this scandal will keep sales way down. Just like OCZ.
  • alaba - Tuesday, March 4, 2014 - link

    Of course, I'm not saying OCZ's later SSDs were the best but they definitely improved but it was too little, too late.

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