It's always seemed a bit strange that the only way to check your faltering frame rate in most games is to grab a free tool like FRAPS. Fortunately, Valve is finally on the case. The latest Steam Beta client update adds an FPS counter overlay.
Added in the January 2 update, along with several improvements to video capture performance, this should (hopefully) avoid issues with third-party software not agreeing with the Steam overlay.
Okay, so it's not the sexiest addition to the Steam client you'll ever see, but it's a very useful one. Little tweaks and improvements to ease of use like this are the reason Valve has such a huge edge over its direct competitors.
That and monstrous sales, of course. Spent so much in the New Year sales that I'll have to forage in the garden for food for most of January. Well worth it. As always you'll need to opt-in to receive these Beta updates in your Steam client. Expect an official release in the next couple of months.
Here's the full list of client updates:
Reduced CPU usage when drawing animated images or videos
Fixed video playback performance regression on Mac OS X and Linux
Added FPS counter to Steam Overlay
Fixed reloading settings values in the Steam Overlay
Improved capture performance in D3D9 games
Improved audio/video synchronization
Improved automatically adjusting video encoding bit rate when a change in available upload bandwidth is detected
Fixed opening the broadcast watch page from client UI (friends list, invite chat message, etc.) in the Steam Overlay
Improved capture performance in OpenGL games when hardware support is enabled on machines with newer Nvidia GPUs
Added first time use and other UI to Big Picture mode
Fixed first friend invite to a broadcast sometimes getting dropped