I evaluated some game recording programs with Quicksync support recently. Bandicam and Mirillis Action produced the best (fastest) results. Some things I want to mention.
I can choose between MPEG-1 L2 and PCM as Audio Codec. MPEG-1 L2 appears to be CPU heavier resulting in a 2-3 fps drop while recording compared to PCM. PCM is uncompress of course but AAC or AC3 should be a better match than MPEG-1. Mirillis Action uses AAC afaik and it's faster (about as fast as Bandicam with PCM audio). Would be nice if Bandicam could do AAC/AC3 in the future.
About Quicksync video parameters. VBR quality based is recommended from Bandicam. Quality 100 appears that it records with 10-12 Mbps while CBR can go up to 20-30 MBps. VBR bitrate mode with higher bitrate support and on Haswell with mbbrc or extbrc support would give much better results regarding video quality, especially on Haswell as long as mbbrc/extbrc is supported. Lookahead might be even better quality wise on Haswell but it uses more CPU and system memory which is not wanted in a game.
I forgot one thing to ask, which Target usage is Quicksync using while recording? About target usage here is a good overview: http://newsroom.intel.com/servlet/JiveS ... s-4200.pdf
edit:
Just tried a different game and quality 100 recorded the game with 93 Mbps, looks like it depends on the game. I noticed Bandicam records in baseline profile. Is this intended because of device compatibility? I know from Quicksync tests that the high profile is noticeably better regarding video quality.