Support Blog

Testing Other Components

Recently, we've discussed testing disks and RAM with Techtool Pro. In addition to testing these important areas, Techtool Pro also tests some of the lesser-known components that keep your Mac running smoothly. Your Mac has a number of sensors that monitor the voltages and temperatures going to your Mac's various components. If things get too hot, most Macs utilize fans to keep things cool. And, if your Mac is a laptop, it has an internal battery used to power the device if the power cord is disconnected.

Fan Sensor Batt

Keeping an eye on some of these systems outside of RAM and disks can assist in identifying other areas that may be keeping your Mac from running its best.

Read more: Testing Other Components

What about my RAM?

We spend a lot of time talking about drives. And indeed, Techtool Pro includes a number of tests and tools for them. However, perhaps the next most important component when it comes to your data is your Mac's memory (RAM).


Your RAM is temporary storage used to store whatever your Mac is currently working on. Since the operating system can hold on to memory used by other processes that have recently been closed, the Memory Test in Techtool Pro reclaims as much memory as possible before testing. Any memory currently in use by the operating system or reserved by a running application is unavailable for testing. To test the most RAM possible, it is best to quit any running applications. Even better, start up from an eDrive or Protogo device, which have slightly smaller operating system footprints.

Read more: What About RAM?

Is your life raft ready?

Many of us will eventually experience that sinking feeling, a never-ending spinning beachball. Even worse, when testing reveals an error in the Volume Structures test. Making repairs to your startup disk requires starting up from a separate disk, which exactly the scenario that an eDrive or Protogo device is designed to fill. If, at this point, you have an eDrive or Protogo device, you will be well situated to get your Mac back up and running. You'll have a life raft.

eDrive Protogo

If an eDrive or Protogo device isn't already available, you can end up caught in a catch-22. There are times when creating an eDrive or Protogo device fails because the basis for that device - your internal hard drive - is unable to copy the necessary files. So it's especially important to be prepared and create your eDrive or Protogo device in advance of hard drive problems.

Creating an eDrive starts with the eDrive tool. Simply select the destination device (an external drive is the better option if using Mojave or later), and click create eDrive. Techtool Pro will add a new partition to the drive, and then copy the necessary components to make a valid startup disk.

Read more: Is Your Life Raft Ready

What are Volume Structures?

Now that most of us have GPS enabled devices in our pockets, it is (mostly) straightforward to find our way when we're out on the road. When it comes to your hard drive, macOS needs its own GPS to find where your files are located when you need them. This GPS, or map, is how you can think of your drive's volume structures. When the map is damaged, your system loses its way and may be unable to navigate to your important files.

Catalina Drive Map

For most Mac drives, volume structures come in one of two "flavors," Mac OS Extended or APFS. If you are using macOS High Sierra or later, your startup drive uses the newer APFS. While APFS adds new features to better support the solid state drives used in almost all modern Macs, Mac OS Extended can still be found on many external storage drives.

Read more: What are Volume Structures?

Predicting Hard Drive Failure

Here at Micromat, as you might imagine, we're pretty good at destroying drives in our computer testing lab. The rigors of software development, as well as testing Volume Rebuilds and Optimizations often take a toll. Some of the machines in the office are on their third or even fourth internal hard drives. More often than not, a SMART warning gives us the early warning we need to keep our Macs running.


A while back, one of the Mac minis in our lab was starting to boot up more slowly than it used to. After checking the drive in the Mac mini using Drive Scope, we found that it was reporting a SMART warning. On further inspection, the drive was reporting over 100 uncorrectable ATA errors and a number of pending relocated sectors, indicating that the drive could soon begin reporting bad blocks. And sure enough, within a month the Surface Scan test in Techtool Pro was reporting bad blocks. We were able to replace the rotational hard drive in this older laptop with an SSD, so it starts up faster than ever.

Read more: Predicting Hard Drive Failure

Page 2 of 5