Mixed Workload & Steady State
80 Percent Sequential Mixed Workload
The mixed workload results are more definitive than the 100 percent read and write tests. Rarely will you ever just read or just write data without mixing up the operations. According to an Intel document we have, an 80% read workload represents normal client use. So, we stick to that for measuring our blended test.
Again, the 480GB BX200 lands at the low end of our chart, with the SLC buffer causing performance variability.
80 Percent Random Mixed Workload
Mixed random data yields similar results from the 480GB BX200, and the 960GB drive posts numbers that look a lot like the lower-capacity drives we tested.
Sequential Steady State
Our mixed sequential steady state tests tell us a lot about performance when the drives are nearly full. Without a lot of spare area to keep cells clean, the drive must perform more read/modify/write cycles. Nearly all of the TLC-based drives lose a lot of sequential write performance.
Random Write Steady State
While combing through the results, I looked at our random steady state numbers and was shocked to see the BX200 writing 4KB data at rates as low as 300 IOPS. We have 7200 RPM mechanical disks in the lab that fare better. None of us will ever get an SSD into steady state using random operations, but we use this metric to evaluate a drive's suitability in RAID. If the line is steady across the x-axis, there's less variation under load. Needless to say, though, Crucial's BX200 isn't a good choice for your next array.