I mentioned VLC because maybe also someone other tesing CoreAVC will have same problem so he will know why encoded file is skipping in circle
And in my case it was VLC which played video on background. But maybe it was problem of Nvidia drivers, who knows?
When talking about performance: when you are encoding, always you need to decode it so it can be passed to encoder from decoder part. It is not problem to decode faster than in real time for CoreAVC. Encoder will ask for decoded frame and it is passed to encoder. There is no decoder fixation to do it in realtime only(you can see it also when timecodec is used). Because that last test can be encoded at about 20% faster because CPU ignores decoding part so there are more cycles for encoding part and also CPU is not so overloaded with CUDA enabled when encoding is in progress.
My GPU is notebook variant of Nvidia 9650m GT.
About DiAVC I already posted here but it is not supported by MEncoder for now so useless for PMS sevrer.
But I didn't test it again with new dsnative.dll driver and latest MEncoder version....older versions were unable to load DiAVC decoder.
Link to timecodec benchmarking "tool": http://haali.cs.msu.ru/mkv/timeCodec.exe