Firmware 1.5: Iometer Test File Monitoring
After secure erasing the Vertex 4, we created a test file using Iometer that filled the drive with 64 KB sequential blocks and monitored write activity at the physical device using Window’s Performance Monitor.
As the file is created, performance drops when capacity shrinks below 50%. Write speeds, specifically, decelerate from a maximum of maximum of 352.42 MiB/s to a minimum of 64.31 MiB/s.
Next, we place 50% static data on the drive and use Iometer to recreate a test file that fills the remaining 59.5 GB. Once 50% of the still-available capacity is consumed, write speeds drop from a maximum of 356.12 MiB/s to a minimum of 73.31 MiB/s.
Finally, we place 74% static data on the drive and use Iometer to recreate a test file that fills the remaining capacity. Before we can get to 50% of what's left, write speeds quickly drop from a maximum of 363.22 MiB/s. Because this happened so close to when monitoring began, zero writes are recorded before the file transfer starts to peak and drop to around 73.31 MiB/s.
These results mirror our observations using HD Tune.