This page is more specific to Rust client variables and other client specific console commands. Please check out our Rust Server Commands page for console commands related to servers.
perf command allows you to show 3 different performance related counters on your screen.
Perf 1 shows just the FPS counter.
Perf 2 shows the FPS counter and total video memory used.
Perf 3 perf 3 Perf 3 shows the FPS counter, total memory used, and video memory latency I believe. ( Don't quote me on the video latency just yet.)