I was playing some 1080p mkv files and they were giving me stutters on my ps3 so I decided to try out coreAVC instead. I could not detail instruction on how to do it, so I just installed coreAVC 1.8 and then insteall ffdshow and disabled h.264/AVC in decoder config page as someone suggested. Then I went ahead and disabled Mencoder on PMS transcoder setting and enabled AviSynth/ffmpeg. However the avisynth/ffmpeg says "this engine is not loaded". I am a little confused so I went ahead and try playing something on my ps3. To my surprise, my mkv files plays! and to a even bigger surprise, my CPU load on my server went from 80% with memcoder to ~10%, the buffer is filled as soon as I start any mkv, and the info status on ps3 top right corner shows that the content is AVC, with audio stream in DD5.1 48khz, so I am assuming PS3 is now doing it's own decoding? I am still confused, but I am happy with my setting right now. I don't know if I have stumbled on something amazing or not...but seems like this could be a solution for all those who don't have core2duo and decoding is taking a toll on performance?