Good Tool For Experienced Users

This is an excellent tool that provides experienced users with valuable information about the performance of their hard drives, especially whether the drives can keep up with the demands of video at varying formats, resolutions, and bit depths. It was extremely valuable to me as I evaluated the performance of a 1TB SSD when I moved it from my Mac Pro’s built-in SATA II controller to a plug-in SATA III controller. It’s a great way to assure that a SATA III controller is not being bottlenecked by using too few lanes in a PCI Express slot.

My one word of warning about this tool has to do with lifespan of SSDs. The tool will happily run as long as you let it, but SSDs have a limited lifespan for writes. After running for a while, some will show a significant slowdown during the write portion of the test, recovering when the test is rerun later. I recommend that you not start it and walk away. Run it long enough to establish the speed and then stop the test.

Many of the complaints about this tool appear to be from users who are out of their depth. One user complained that it said his drives were read-only. He was almost certainly telling the application to test the root directory of the drive or some other directory to which he does not have write permissions. He should have chosen something like his documents directory or downloads directory. Another complained about it not showing what drive was under test — but it always defaults to the primary drive and only changes when the user selects another drive. Other complaints are inexplicable, with several users bemoaning the large interface and speed indicator dials — just like the screenshot shows! They must be a joy to go to lunch with; “waiter, I want to return this pizza because it looks just like the photo in the menu."

fmaxwell about Blackmagic Disk Speed Test