Not to necropost, but I recently bought several (12+) of these drives and after opening the first 2, I made the same discovery that several users and hardware sites (tweaktown, anandtech, [H], etc) .
Kingston has pulled a bait and switch with these drives.
As an enthusiast, I've got to share the info here, and I STRONGLY suggest TO anyone who has purchased these drives to try and return them.
Here's the story on these.
So back when hardware review sites were sent the v300's to test , Kingston was sourcing the NAND memory from toshiba, 19nm toggle nand. This will be version 5.0.5 of the v300.
Shortly after Kingston switched to asynchronous Micron 20nm NAND, this will be version 5.0.6 and 5.2.1 of the drives.
Let me put it this way, when handling anything other than compressible data, this thing is almost as slow as a 7200 HD. Heck I have some 7200 which trounce the v300. This thing has SATA 1 SPEEDS!!! No joke. reads at around 179 MB/sec writes writes 78 MB/sec . Yap you read the numbers right.
I had both versions of the drives, when running ATTO (i've got pc's setup, duh, that i run benchmarks etc on), which is benching the drive with compressible data, they score beyond the 450/450 read/write that is advertised on the packaging, they hit 525 write/533 read (typical of all LSI sandforce SF2281 based controllers). Being that it is using the SF2281 controller, it handles that sort of data well. HOWEVER that is the least accurate metric to use to judge/qualify a solid SSD for use in the REAL WORLD .
I'm personally going to refrain from purchasing anything from Kingston. I went ahead and got rid of all the drives (via returns to reseller(s)) . I consider this fraud, bait and switch, theft, on Kingston's behalf. They send a solid version of the drive to get reviewed by all the media sites that cover tech, THEN they screw us over by actually selling us FAR INFERIOR merchandise.
Check your drive, bottom right corner above bar code is the version number, anything other than 505 prefix uses the garbage NAND. I recommend purchasers to bench their drives on a win system with AS SSD, crystalmark, or similar. Then comes the call whether to return the drive. Kingston wont RMA, but Newegg has been sympathetic to builders who really feel burned purchasing these drives.