MyDigitalSSD BP4 2.5" & mSATA (240GB) Review

Performance Over Time & TRIM

Our new performance consistency tests give a pretty good indication of performance over time but HD Tach is still a good method for checking TRIM functionality. As usual, I took a secure erased 2.5" BP4 and ran it through HD Tach to get the baseline performance.

Next I filled the drive with sequential data and tortured with 4KB random writes (QD=32, 100% LBA space) for 60 minutes and reran HD Tach.

Performance drops to as low as 20MB/s for the earliest LBAs, which is similar to what the steady state performance looked like in our IO consistency test. Over time, performance gets better as the drive defragments itself and after about 150GB of sequential writes, peak performance gets over 300MB/s. Again, the behavior we're seeing here is related to what we saw in IO consistency tests: there are short peaks and then the drive goes back to do garbage collection.

To test TRIM, I secure erased the drive, filled it and tortured again for 60 minutes to make sure that it's fully fragmented. Then I TRIM'ed all the LBAs:

And TRIM works. Write speed is actually higher than after a secure erase but if we look at IOmeter scores, ~350MB/s is what the BP4 gets. Sometimes drives perform weirdly right after a secure erase. Especially if you're erasing a highly fragmented drive, it may take some minutes for the drive to complete the request, even though it shows up as secure erased.