No rendering or encoding lag but try running your monitor @ 120HZ & make a few changes to your encoding settings. Since B Frames are the lowest quality frame type, get rid of them.
One other thing I checked was the Nvidia driver you have installed, saw lots of performance issues with it. Might be a good idea to update, the current driver seems to be working fine. (552.44)
13:06:33.993: codec: H264
13:06:33.993: rate_control: CQP
13:06:33.993: bitrate: 0
13:06:33.993: cqp: 14
13:06:33.993: keyint: 120
13:06:33.993: preset: p7 > P5
13:06:33.993: tuning: hq
13:06:33.993: multipass: fullres > qres
13:06:33.993: profile: high
13:06:33.993: width: 1920
13:06:33.993: height: 1080
13:06:33.993: b-frames: 2 > 0
13:06:33.993: lookahead: true > uncheck
13:06:33.993: psycho_aq: true > uncheck