There are numerous variables which can contribute to the responsiveness of your Mac. In particular, if your Mac has an SSD, and if TRIM hasn’t been able to keep up with clearing disk space, your speedy Solid State Drive can start to feel like an old rotational hard drive. It might not be immediately obvious, however, without measuring the performance of your SSD. Techtool Pro 13 introduces a new tool to do exactly this.

To measure the speed of any disk connected to your Mac, simply select it from the drive list in the Drive Speed tool, and click the Run Disk Speed button. In addition, there are options to set the size of the load used to measure disk speed, as well as the number of loops utilized by the tool. In most cases, drives usually read and write in small chunks, so the standard settings typically are all you would need. But, if you frequently use large files, or want to see what happens when the write cache is full, consider running the Disk Speed tool using a larger load or using additional loops.

If you’re seeing slower speeds than expected, particularly on external drives, here are some things to check. First, be sure that the external drive is connected using the fastest connection possible. A USB 3 drive connected to a USB 2 port will run much more slowly than advertised in most cases. Second, make sure that there’s enough bandwidth to go around. If there are multiple drives doing large read or write operations at the same time, or more than one copy operation is in progress simultaneously, that can affect actual speeds.

Pro Tip: Avoid running the Disk Speed tool too often, which can add excess wear to your drive.