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128 KB And 2 MB Sequential Performance

Micron's RealSSD P400e: Affordable SSD Storage For The Enterprise?

128 KB Sequential

Micron's P400e serves up sequential read throughput just short of 400 MB/s at a queue depth of one, landing it at the top of the pack. However, as commands start piling up, the performance lead evaporates. With four or more concurrent commands outstanding, the SLC-based P300 roughly matches the P400e's performance at 450 MB/s.

The SSD 520 is the only drive able to punch through 500 MB/s. Intel, as a company, does not dominate in this test, though. The SSD 320 and 710 employ a homegrown 3 Gb/s controller that cap performance under 300 MB/s.

At a queue depth of one, the P400e delivers about 70 MB/s in 128 KB sequential writes, though performance improves considerably as the commands start stacking up, topping out around 240 MB/s. In comparison, the 3 Gb/s SSD 320 and 710 are capable of ~210 MB/s regardless of queue depth.

Intel's SandForce-based SSD 520 pushes about ~240 MB/s when it's presented with incompressible data. That's good enough to best the P400e at low queue depths and match it as requests increase.

Moving to a larger block size minimizes the impact of queue depth. Using 2 MB transfers, Micron's P400e serves up throughput between 5-10 MB/s faster than the SLC-based P300—a respectable accomplishment, particularly as the SSD 320 and 710 are bound by their SATA 3Gb/s interfaces.

Intel's SSD 520 is the only drive able to outmaneuver the P400e with a sequential write speed close to 550 MB/s. Incompressible data has little effect on the SSD 520's performance; read speeds only fall by ~10 MB/s.

Sequential 2 MB write results are similar to what we saw from the 128 KB sequential writes, but without the impact of queue depth weighing on performance. Intel's SSD 520 still reigns supreme when it's presented with compressible data. Incompressible data knocks it close to the bottom of the chart, though.

Micron's P400e performs modestly, coming close to matching the SSD 520's performance with incompressible data.

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