Mixed Workloads & Steady State
80 Percent Sequential Mixed Workload
Mixing sequential reads and writes separates the drives more than the 100 percent read or write workloads we just saw. At a queue depth of two, the M6V outperforms the other products in our chart. By a queue depth of four, Samsung's 850 EVO moves to the top, though the M6V remains close.
80 Percent Random Mixed Workload
Mixing in random data spreads the field of low-cost SSDs even more. We've known for a long time that the 850 EVO is better than the competition when it comes to performance metrics that matter. Plextor's 256GB M6V closes the gap, but fails to achieve the same level of mixed random throughput that Samsung's 850 EVO delivers.
Sequential Steady State
The next two sections employ difficult workloads that follow long conditioning periods. Most of the folks interested in entry-level SSDs will not get their drives down to these conditions; it takes a professional application to push performance this low. With the SSDs nearly full, however, it's easier to get them into a steady state condition, and that may be a concern for some users.
The M6V performs well in this test, but only compared to other low-cost models. Drives like the SanDisk Extreme Pro and the Samsung 850 Pro fare much better than the models we're charting.
Random Write Steady State
The random write steady state test has two purposes. First, it determines how far IOPS can drop. Second, it allows us to measure performance consistency. Again, most PC users will never see performance fall to this level. But we know that a consistent showing here is indicative of better RAID performance in a striped array. Ever since Intel released drivers that enable TRIM in RAID 0, low-cost solid-state arrays have become more popular.
Plextor's M6V exhibits a low ceiling and a fairly high (for this price range) peak. These drives would not make good candidates for RAID arrays because most of the random write IOPS happen at the lower tier. However, this drive does generate higher steady state random write numbers compared to most of the TLC-based drives. Samsung's 850 EVO is the exception.