80 Percent Sequential Mixed Workload
The Plextor M7V 512GB SSD suffers from low-to-average sequential read performance, and that carries over to the sequential mixed workload test. Most of the other TLC-based products, including the M7V, have trouble with performance scaling as the workload intensifies.
80 Percent Random Mixed Workload
We were surprised to see the M7V perform so well in the mixed random test. The SSDs ranks in the top three at high queue depths, but at lower queue depths the drive delivers average performance that trails the two Samsung products and the Mushkin Triactor (Phison S10 + Toshiba 15nm TLC).
Sequential Steady State
As we mentioned previously in the review, the Marvell Dean suffers from low performance during some workloads. The four-channel controller cannot match other four-channel products during heavy workloads, such as the SMI SM2256 and SM2258.
Random Write Steady State
The Plextor M7V delivers consistent random performance under steady-state conditions, but the performance level is very low. The low performance wouldn't be ideal for use in consumer RAID arrays. It would be more economical to purchase a faster and larger mainstream SSD (like the Samsung 850 EVO) if you are looking to double performance and capacity.
PCMark 8 Real-World Software Performance
For details on our real-world software performance testing, please click here.
The Plextor M7V falls near the bottom of the results with daily use software. We observed the drive taking more than a second longer than the other drives to finish a task in many of the tests. The M7V performs slightly better in some of the lighter tests, but it still trails many of the other entry-level products.
Throughput Storage Bandwidth
In this chart, we combined the results of the ten PCMark 8 tests to determine the average throughput. The Plextor M7V is nearly 100 MB/s slower than the Samsung 850 EVO, and 90 MB/s slower than the newly released Samsung 750 EVO 500GB.
PCMark 8 Advanced Workload Performance
To learn how we test advanced workload performance, please click here.
This series of tests uses the same real-world applications as the previous tests, but it applies preconditioning to show steady-state and recovery phases. Without a sizable overprovisioned area, the Plextor M7V has a difficult time keeping pace with the other products. To my knowledge, the M7V is the only consumer TLC-based SSD sold without at least 7 percent overprovisioning. The additional capacity looks good on the specification sheet, but performance suffers even when the drive has time to clean dirty cells during the recovery phases.
The M7V has very high latency during light workloads. The M7V wouldn't be my first choice for a low-cost SSD for any system, unless it is used solely for web browsing or very light workloads. We often hear from readers that they have a difficult time differentiating between one SSD and another. You can see on the moderate service time chart that many SSDs deliver similar performance where it matters, but the Plextor M7V is an exception. You would easily feel the increased latency with this SSD compared to many of the others.
Notebook Battery Life
The Plextor M7V has the worst battery life of the forty SSDs we've tested thus far in our new Lenovo Y700 17-inch notebooks. We tested a notebook-optimized hard disk drive from Western Digital (WD Slim 1TB), and even it delivered two more minutes of battery time. The Plextor M7V did deliver a higher system performance score than the hard drive, but it trails all of the SSDs we've tested.