The Plextor M9Pe NVMe SSD Review: Teaching An Old Chip New Tricks

Sequential Read Performance

Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.

The burst sequential read speeds from the Plextor M9Pe are worse than most NVMe SSDs including the low-end MyDigitalSSD SBX, but at least it's still well above SATA speeds (unlike the Plextor M8Se).

Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data.

On the longer sequential read test, the M9Pe fares a little better as the MyDigitalSSD SBX and Intel SSD 760p drop down to about the same level. As with the burst test, the Samsung drives dominate.

Power Efficiency in MB/s/W	Average Power in W

The Plextor M9Pe's power efficiency on the sequential read speed is below average, but it's not actually the worst-scoring NVMe SSD for this test—that distinction belongs to the Intel SSD 760p, which is barely more efficient than the Crucial MX500 SATA SSD.

Plextor M9PeY 1TB (M.2)MyDigitalSSD SBX 512GBIntel SSD 760p 512GBSamsung 960 PRO 1TBSamsung 960 PRO 512GBSamsung 970 EVO 500GBSamsung 970 EVO 1TBPlextor M8PeGN 512GBPlextor M8SeY 1TB (M.2)Plextor M9PeGN 512GB (M.2)Western Digital WD Black 1TB (3D NAND)Intel Optane SSD 900P 280GBPlextor M9PeY 1TB (AIC)Plextor M9PeY 512GB (AIC)Crucial MX500 1TBCrucial MX500 500GB

Both M9Pe models hit full sequential read speed at QD4, which is relatively late, but not as slow a ramp up as the WD Black shows.

Sequential Write Performance

Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.

The burst sequential write speeds from the Plextor M9Pe are good, with only the WD Black and a few Samsung drives scoring better. The older generation of Plextor drives performed much worse on this test.

Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.

On the longer sequential write test, the M9Pe manages to stay ahead of the low-end NVMe drives but otherwise doesn't perform well. Capacity is a major factor in performance here: the 1TB model is 80% faster than the 512GB model.

Power Efficiency in MB/s/W	Average Power in W

With almost average performance, the 1TB M9Pe has reasonable but not top-tier power efficiency on the sustained sequential write test. The 512GB model has the second-worst efficiency score out of this batch of drives.

Plextor M9PeY 1TB (M.2)MyDigitalSSD SBX 512GBIntel SSD 760p 512GBSamsung 960 PRO 1TBSamsung 960 PRO 512GBSamsung 970 EVO 500GBSamsung 970 EVO 1TBPlextor M8PeGN 512GBPlextor M8SeY 1TB (M.2)Plextor M9PeGN 512GB (M.2)Western Digital WD Black 1TB (3D NAND)Intel Optane SSD 900P 280GBPlextor M9PeY 1TB (AIC)Plextor M9PeY 512GB (AIC)Crucial MX500 1TBCrucial MX500 500GB

The sequential performance of the Plextor M9Pe increases slightly from QD1 to QD2 and is steady thereafter, with no obvious signs of SLC write cache exhaustion or intermittent garbage collection getting in the way.