[goujam]

Yes, that file buffers over XBMC NFS mounts in Beta5, but it's only utilising 25% of the network (2.5MB/s), and the CPU is pegged at 100% so I doubt a Gig NIC will help here unless it can somehow reduce the CPU load.

The file plays fine from SD card (Class 10, Transcend) as the Pi doesn't have to expend CPU cycles in order to service the USB interrupts caused by the network traffic, although even from SD card the Pi (overclocked 1000/500/600) will come close to exhausting the audio queue so only narrowly avoids a stutter. When playing back from the network, the audio queue does become exhausted resulting in a stutter/buffer, simply because there isn't enough CPU available to get the data in time from the network and also decode the video/audio.

It's not really a case of the Pi NIC having insufficient bandwidth to play the movie, more a case of ethernet-over-USB being a rather inefficient (but cheap) design from a CPU loading perspective, and I doubt a different USB NIC will help here, but do let us know how you get on if you take this route.

Thanks for your feedback its most helpful, I assumed that it was network speed slowing it down. Why do you think the CPU is at almost 100% all the time? Is it the fact it needs to extract the DTS core from the DTS-MA, If so im sure that if we get the DTS-MA pass thru liecence this file should play fine.

It also explains the reason why SMB is so terrible at plaing this file due to the extra cpu load.