Regular visitors to Vortez in the past will have had a hard time discerning which SSD is best bast on read speed because for all intents and purposes there wasn't a massive amount between them, certainly not in any 'real world' scenario. Sure a few MB/s here and there can differentiate them but it's not as though say 20MB/s is going to make a massive amount of difference unless you are a benchmark junkie. The thing is, serial ATA's 6GB/s limitation means that most drives will score on average around the 500MB/s mark, meaning one drive perform close to the next unless RAID 0 or SCSI is implemented. The problem is that SSDs as we know them have always been 'crippled' by legacy protocols which have been based on old architecture. Upon SSDs being released this was never an issue due to the fact they were so much faster than their mechanical brethren but as time has passed, even the cheapest drives are now showing tremendous speed whereas the flagship models no longer hold the advantage they once did. Not because the drives are physically the same but because of the protocols/architecture in use so much so that many manufacturers began to concentrate more on durability and sustained speed rather than out right performance figures.
Enter PCIe. Primarily used for high bandwidth items such as graphics cards, PCIe and the massive amount of bandwidth afforded has slowly been utilised such as with the OCZ Revodrive and Plextor's M6e we reviewed recently. While performance was enhanced and actually looked very impressive when compared to the SATA devices due to the enhanced bandwidth available, they were essentially still restricted in some form because of the SATA protocol.
Non Volatile Memory Express (NVMe) work differently than SATA. For starters it can take advantage of parallelism through PCIe. With most devices expected to use the PCIe x4 socket this means that four lanes are available for use which also dictates that multiple CPU cores can also be used and thus multiple applications. Queue depth is massively increased as a result. For example, SATA (AHCI) is limited to 1 command queue with 32 commands per queue. In comparison NVMe can have up to 65536 queues each with 65536 commands per queue! This is one of the rare occasions that a queue (or rather 65536 queues)is not a bad thing!
If you prefer the standard SSD sizing rather than a card format don't worry because NVMe will also take on the format of a 2.5" drive but instead of using a SATA connection, the four-lane PCI Express interface through an SFF-8639 connector. Also, if you are worried about drivers, don't be. While it is true that you would need a compatible driver for anything Windows 7 or older, Windows 8.1 has NVMe drivers included as standard. The main issue as we see it with the uptake of these drives is the BIOS of motherboards. Some manufacturers are very slow in updating their products which will mean that until there is an updated BIOS for your NVMe drive, you will not be able to boot an OS from it. Thankfully we are starting to see compatible BIOS' appear but it is worth checking beforehand if using the NVMe drive as a boot device is your intended purpose. If you do not have a compatible BIOS, the NVMe drive can still be used as a normal DATA drive. This is not going to be a 'here today-gone tomorrow' fad that's for sure. Expect this to rapidly become the norm. Apple Retina products already support NVMe as standard and we expect Windows based devices, if not already, to follow suit.
