Hi,
SHADOWPLAY is coming to NVidia GTX600 and 700 series cards in the near future.
http://www.geforce.com/whats-new/articles/geforce-experience-official-release
It uses the NVENC hardware decoder on the graphics chip for minimal performance impact (5% or less likely) so your frame rate should stay at 60FPS.
It was supposed to be out this summer though they claimed they delayed to use the more compatible MP4 container instead of M2TS. A good idea. The only details I know are:
- H.264 video codec
- MP4 container
- 1080p @30FPS (unknown if 60FPS is available at 1080p or 720p)
- can stream or record to drive
BTW, since you said you were "over 60FPS" you likely don't have VSYNC ON. I recommend doing that.
I don't know if using a RAM CACHE would aid you at all now or with the Shadowplay solution to prevent any stuttering due to simultaneous drive access with the game and recording.
Currently:
Your bottleneck is the impact on your CPU for software rendering of the video. Any settings in the program will affect that. Resolution, quality etc. though I don't use this type of software.
You may even wish to use the ADAPTIVE HALF VSYNC option in the NVidia Control Panel to run at 30FPS (VSYNC at 30FPS but disable VSync if you drop below). Since you're dropping this low anyway it may give you a more consistent experience until Shadowplay comes out.
VSYNC however cause the game to feel more sluggish at 30FPS especially but the advantage is disabling SCREEN TEARING. It depends on what's more important to you.