More than a decade has passed since PATA (Parallel ATA) was made redundant by SATA. Originally designed to provide a maximum throughput of 16MB/s, PATA and was eventually upgraded to 133MB/s, which may still seem like plenty when you consider today's desktop local area networks are still limited to ~100MB/s using Gigabit Ethernet.
And at the time, 133MB/s was plenty. No devices could achieve that kind of throughput for a few reasons. First, PATA used the PCI bus which was shared with many other devices, all of which were competing for bandwidth. This congestion on the host bus limited the maximum burst transfer rate and no hard drives could sustain transfer rates of above 80MB/s -- even by 2005.
However, as early as 2003 desktops were pumping 3GB/s of bandwidth between their system memory and processor, while graphics cards were exceeding 30GB/s. It became clear that hard drives were the weakest link of modern computers and that if PCs were going to get faster, the biggest boost would come from rethinking primary storage.
In turn, companies dumped the parallel design for a serial interface, SATA, and by 2010 we saw 10,000 RPM hard drives reaching 130MB/s of sustained data transfer, a little over 60% more than what was seen previously using PATA. Unfortunately, while they were faster, those high-speed hard drives were also hotter, noisier, pricier and less capacious than slower spindle drives.
Still unable to max the original SATA interface, conventional hard drives had little hope of tapping SATA 2.0's 300MB/s allowance, much less SATA 3.0's 600MB/s, yet those speeds have already grown inadequate for the quickest flash drives. This brings us to SATA 3.2 and its ample 16Gb/s bandwidth, which is offered via SATA Express and SATA M.2 on Intel's new 9-series chipsets.
SATA M.2 is particularly interesting with drives similar to mSATA SSDs, which were introduced with SATA 3.1, except that M.2 supports higher speeds. In the case of Asrock and its Ultra M.2 socket, which is connected directly to the CPU, we're talking about a bandwidth of up to 32Gb/s, while the standard M.2 socket still provides 10Gb/s. Now we just need faster flash drives.
Following up on its M1 and M2 series, Plextor's new M6 range puts custom firmware, Toshiba NAND flash memory and a Marvell controller in three different packages: