If you have two sticks of RAM, run the diagnostic with only one installed at a time. This helps you identify which specific stick is broken.
Press on your keyboard to start the diagnostics. For Intel-based Macs: Shut down your Mac. Turn it back on and immediately press and hold the D key .
Use the included "ImageWriter" to install the tool onto a spare USB drive. how to run memory diagnostics
Select to start the test immediately (save your work first!).
If your computer is suffering from the "Blue Screen of Death" (BSOD), frequent crashes, or mysterious slowdowns, your RAM (Random Access Memory) might be failing. Faulty memory can cause data corruption and system instability, but luckily, testing it is straightforward. If you have two sticks of RAM, run
Restart your PC and enter your BIOS/UEFI (usually by tapping F2, F12, or Del during startup). Set the USB drive as the primary boot device.
Apple includes a built-in diagnostic suite that checks RAM along with other hardware components. For Apple Silicon (M1, M2, M3): Shut down your Mac. For Intel-based Macs: Shut down your Mac
Select if you want to finish what you’re doing first.