Playing 1080p MKV Files

[dogfood09]

Hi Guys

This is my first post on these forums , So sorry if this question has been asked before or its in the wrong forum.

I am having issues playing 1080p MKV files , I have been using VLC Player , but i dont think it handles the file very well as it keeps stuttering , I can play normal blu-ray disc fine using Powerdvd , But these mkv files seem to struggle playing , I wont play in power dvd , but i do get somewhere with vlc , although not very well , Does anyone have any suggestions what i should do? I have a radeon x1950 512mb Card , Have not adjusted any settings whatsoever , Is it the hardware i am using , although it plays blu-ray fine or is it the software and my settings? Any advice would be great , all 720p files play without a hitch , its just the 1080p ones ! Wether or not it helps but this is my rig

Radeon x1950 512mb ( latest drivers included )
3gb ddr2 ram
Core duo 2 CPU
Toshiba 37" regza full hd tv as monitor

Any ideas?

Regards
Dog

[neuron2]

How did you make the MKV files?

[linyx]

Check out CoreAVC or the DivX Decoder for playing them, they won't work in vlc though, only mpc or any other ffdshow based player.