How often do you pull you hair trying to find out which tab in your browser has a flash video open and is driving your CPU fans crazy? Or why your browsing speeds are so slow, only to find out after a lot of switching applications that you forgot to pause your BitTorrent downloads? In all such situations, a process or activity monitor comes in handy to quickly find the culprit behind the problem and resolve the issue.
Mac OS X comes bundled with an Activity Monitor (which you can find in /Applications/Utilities), but this app is rather basic and has a lot of limitations.
atMonitor is a free app that allows you to easily monitor CPU usage, GPU usage, RAM usage, network stats, temperature, disk usage and a lot of other stuff. As soon as you launch atMonitor, you’ll see a floating widget, which displays a lot of real-time graphs and the icons for the top 3 CPU-hogging processes.
This is a useful tool but rather too big and colorful for my taste, and after a while can become annoying because it also lingers across Spaces and stays on top of all applications. Thankfully this widget can be customized or completely disabled from the Preferences.
atMonitor also places graphs/stats in the status bar, which is similar to iStat Menus. Personally, I would prefer iStat Menus over atMonitor anyday (even though it is now a paid app) because iStat Menus is much better designed and gels well with the monochrome Mac OS X menu bar.
The main window is probably the only useful part of the atMonitor bundle. A quick filter search box on the top right allows you to quickly filter out processes and pause/kill them. You can also sort processes by CPU usage, memory usage, thread, user, version or priority. There is also a quick ‘reveal’ button in the main window which takes you to the .app file for the selected application in Finder. The Info button opens up the relevant app link on iusethis.com in your browser.
Overall, atMonitor is a nifty tool, but does not make a mark because of poor design and overall lack of intuitiveness and ease of use.