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.



View All Comments

  • compdoc - Wednesday, April 2, 2014 - link

    On 3/22/2014 I purchased a Kingston SSDNow V300 Series SV300S37A/240G, and it benchmarks at 520 reads and 380 writes on a low cost A8-6600K system. Cost me $110 at newegg, so I'm very happy with it. Just old inventory? I'd love to hear what other owners are seeing. Reply
  • hojnikb - Friday, April 4, 2014 - link

    Try as-ssd or crystaldiskmark random data and report back :) Reply
  • apothec - Friday, May 9, 2014 - link

    I read this article, but i decided to buy a V300 240gb anyway. Mainly because of the price (150$ in my country) and i though i might get lucky with the firmware. I thought wrong. FW 521 has in ASssd and CrystalMark about 160-185 read and 190-240 write. In Atto is great, 400-550. But almost all ssds perform like that in atto so i dont take it as a real benchmark.

    Now i wait to return the product because im the 10days waranty when i can return it no questions asked. Il go with the Samsung Evo 250gb or Adata's sx900 256gb. Still thinking which one suits me best (tlc vs mlc).

    Kingston ssd, no more for me. Just sticking to ram. Even the Crucial m500 has more speed than That v300 new FW. An its cheaper!
  • kugo2006 - Tuesday, May 13, 2014 - link

    So if you did get the 506 or 521 firmware version, is there a [relatively easy] way to downgrade to the 505 or 520? Or perhaps upgrade to a newer version? Reply
  • GraveNoX - Tuesday, May 20, 2014 - link

    5 months ago I got 120gb drive with 506 fw and I paid $130 for it so imagine how SAD I am. I have gigabit home connection and I get 30 MB/s at max with V300 and 110 MB/s at max with 2TB HDD, but wait, I got faster boot time!!! This crap ssd should not be sold. Reply
  • Colorado_Al - Tuesday, May 27, 2014 - link

    Here is Kingston's Official response to my query:
    Kingston said:
    I can certainly understand your concern but it's important to understand why this is. Crystal Disk and AS SSD uses incompressed data during its testing. The data cannot be compressed further so much without the write speed being affected. Because both of these benchmarks use fully incompressible data they are nowhere near a real world workload for typical desktop-notebook computing. ATTO disk benchmark uses uncompressed data. So the Sandforce drives can perform its compression and thus the increased speed of this drive is reflected in the benchmark. It is also the program used by our engineering staff to document the speed ratings for the these drives during testing. Unfortunately CDM gives a different lower score with these Asynchronous NAND but does not mean the drives are subpar in any way, form or fashion. Just different testing methods used by these benchmarking software. If CDM tested the same as ATTO using uncompressed data there would be no problem.
  • GarthBock - Thursday, May 29, 2014 - link

    I have seen this posted in other forums last year including one where a Kingston rep denied there were performance issues and denied they were screwing their customers. Reply
  • the_law - Wednesday, October 8, 2014 - link

    I just got one of these drives before reading all about this. To add insult to injury, my drive appears to have been used. There are clear scratches around one of the screw holes. This despite it coming sealed in its package. Reply
  • Encho - Saturday, February 14, 2015 - link

    Kristian, is there any update? I trusted this darned brand and bought it a some days ago, haven't received the units, but I suspect it will be the slower type. Reply
  • JohnnyFingers - Monday, March 30, 2015 - link

    I think maybe synchronous VS asynchronous NAND longevity is a more serious issue too?? Reply

Log in

Don't have an account? Sign up now