GPU Usage - What's making it spike

Hi Gang,

I’m wondering if there’s any way to tell exactly what’s using 83% of my GPU? I’ve been using iStat Menus for years, which provides a lot of useful information about what’s happening with my Mac (it’s kind of like Activity Monitor but on the Menu Bar). I recently added the GPU monitor, and wow, it’s always pegged, even when no applications are open. Unlike the other iStat menu displays, GPU doesn’t show what’s pegging it.

Does anyone have any ideas on how to determine what’s making the GPU go crazy?