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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  • jabber - Tuesday, March 4, 2014 - link

    But when 99% of folks are just used to that old 2005 4200rpm 120GB HDD that pushes 50MBps there are plenty who will think that Pulse SSD heavenly.
  • psiboy - Sunday, August 2, 2015 - link

    That's called Fraud! Criminal charges would be laid here in Australia!
  • Subyman - Monday, March 3, 2014 - link

    Did they update the packaging? The previous V300 shows "up to 450MB/s" on the box. Obviously, that is no longer possible.
  • hojnikb - Monday, March 3, 2014 - link

    Well, they are using compression, so under certain scenarios (like highly compressable data) this drive will perform indentical to older one.
    So yeah, this is a dick move Kingston..
  • Flunk - Monday, March 3, 2014 - link

    Based on the wording you could write "up to 1,000,000MB/s" and still be legal. "up to" is the weasellyest wording in the industry.
  • Kristian Vättö - Monday, March 3, 2014 - link

    Kingston uses ATTO for the marketing benchmarks and there is no slowdown since it's all compressible data.
  • hojnikb - Monday, March 3, 2014 - link

    Exactly my point. They could stick the lowest grade flash in there and it wouldn't change the score in atto.
    Atleast they could use micron's sync flash.
  • mapesdhs - Monday, March 3, 2014 - link

    Indeed, Atto is a poor test of an SSD. Using AS-SSD, a 60GB Vertex2E
    is half the speed of a 240GB Vertex2 for sequential write, about 43%
    slower for seq. read, etc., yet Atto gives almost identical results for both
    models. It's no wonder vendor marketing people use Atto for their PR.

  • dpjtpa - Sunday, October 1, 2017 - link

    In working for corporate America for 15 years I definitely agree with you. Any company that has decently savvy bloated management structures in place will definitely be able to handle "cooking the books".
    Once I handled a specific city/market where the sales results were the absolute worst in the entire company and we were a Fortune 30 company operating in all 50 states. Despite the massive capital outlay, the return on customers paying revenue was embarrasing. The amount of outside sales reps got doubled for this market while the quota got cut in half from the prior year. None to my surprise, I listened to my boss "proudly" present to our VP's our great trends and traction we were gaining.....He presented Year over Year growth in attainment to quota. Well, if the quota is 50 instead of 100 then I can sell 25 widgets this year versus 50 widgets last year and my year over year comparison would be 50%. No change on the cover, but in reality it is half the revenue being brought in from the previous year. There is a study, a graph, an expert, a Sean Spicer, and a template to make the most convincing argument in the present day. Kingston will suffer and Trump is being unmasked as well. It's only a matter of time
  • wicketr - Monday, March 3, 2014 - link

    Imagine buying a new laptop, and instead of getting that Intel i5 processor you expected to be in it, the laptop manufacturer swapped it out with some cheapo AMD Opteron to save them money. This is pretty close to the same thing.

    You can't knowingly release a product that is >50% slower than advertised speeds and not suffer severe consequences.

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