I'm looking for an alternative to diskLED because diskLED keeps failing with an error message. So, I tried Atlas. diskLED would flicker during disk activity, but Atlas did nothing; I assume it's not sensitive enough to detect short bursts of hard disk activity, or doesn't work on SSD drives.
Hardware Lister - lshw (Hardware Lister) is a small tool to provide detailed information on the hardware...
DiskLED - DiskLED is a flexible hard disk and general system activity indicator system tray applet.
iStat Menus - "An advanced Mac system monitor for your menubar."
HDD Led Indicator - This is a hard disk activity monitoring tool.
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.
DriveGLEAM - DriveGleam is a free app that installs a handful of activity indicators as icons in your system...