My pc is actually a Pentium D 2.8ghz not core2duo.. could that be the problem?
I just tried my dell m1330 laptop which is core2duo 2ghz and so far there is no lag or stuttering. But the laptop cpu is running at about 90%. I have tried installing coreavc but in task manager it says ffmpeg.. whereas with mencoder it had mencoder. Is ffmpeg coreavc?
So maybe I need to upgrade my main pc to a core2duo as it looks like it works better.
edit: my dell has nvidia 8400gs built in so updated the driver and avisynth was still showing 90%+ cpu usage.. changed back to mencoder and it is now sitting at 20% max for cpu!!
so looks like I have answered my own question... need to get a core2duo cpu for my pc and nvidia graphics card. What do you recommend I get for cpu and graphics card bearing in mind I don't play any games on my pc, all I want it to do is transcode 1080p mkv's to my ps3. Buffer is now sitting at close to full, is this a good thing or bad thing?