Once selected, click the large Speed Test Start button. Select the option you wish to use from the list. Once you select the drive, the next step is to select the Stress level that your hard disk will be tested to. Fortunately options are few so all you have to do is select the drive you wish to test, in case you use external storage for your video editing or you have multiple drives on your Mac. You will also find that there’s a gear icon between the two gauges that points to the app’s options. When Speed Test launches you will find yourself staring at two large speed gauges that measure your hard drive’s Write and Read speeds. Open Launchpad to find DiskSpeedTest and launch it. Download and install the free application from the Mac App Store. Disk Speed Test by Blackmagic allows you to quickly measure and certify your disk drives for working with video. The application is designed to determine how well you hard drive will fare while editing large files, specifically. Want to find out how well your hard drive will fare while working with video editing applications on your Mac? Looking for an excuse to buy an SSD for your Mac? Download Disk Speed Test.