These increased slightly with two Finder windows, and with Safari displaying its Start Page or website in a single window. With a single Activity Monitor window open, WS was slightly more demanding in its CPU and memory use than on the iMac Pro, with 2.1% CPU and 192.1 MB memory. Closing that window and quitting Safari returned WS to 0.9% and 185.8 MB memory usage, leaving the latter slightly higher than it had been before Safari had been opened (158.2 MB). With all 20 converted to tabs within a single Safari window, CPU remained at 1.2% and memory fell back slightly to 207.2 MB. When all 20 windows were minimised into the Dock, CPU fell to 1.2% but memory increased further to 214.1 MB.

These give a good linear regression with an overall memory cost of 1.7 MB per Safari window. Adding further Safari windows steadily increased both CPU and memory usage: Safari, with a single page open, either its Start Page or a website, had no effect on CPU, and increased memory usage to about 165 MB. Adding two large Finder windows increased memory use slightly, to 158.2 MB, but didn’t affect CPU. When freshly started up with a single Activity Monitor window open, WS used around 1% CPU and 154.6 MB of memory. Safari windows had full options, including the Bookmarks sidebar, Favourites and Status bars, and occupied the majority of the screen. Web pages used were rich in content, with static images and text, but none contained streamed video or similarly demanding media.

Both were set at their default display resolutions, and had been freshly restarted in Monterey 12.2.1 before testing. To assess this, I looked at the CPU % and memory usage given by Activity Monitor for the WindowServer (WS) process on two Macs: an iMac Pro with 32 GB of memory, Radeon Pro Vega 56 8 GB graphics and its standard 5K 27-inch display an M1 Pro MacBook Pro with 32 GB of memory and its standard display.

This article looks at WindowServer’s use of resources in Monterey 12.2.1, on both Intel and M1 Macs, to see if there’s evidence of a problem. A few have suggested it might have a memory leak, although no one has provided any evidence to support that. Several of you have reported that WindowServer hogs your CPU, and may consume large amounts of memory too.

Windows server macos activity monitor