I have a Mac Pro Octo-Core @3.0ghz w/10gigs of RAM and 8800GT video card. When I load up a 5DMkII video, the playback seems to skip every few seconds and even after transcoding it to XDCAM EX, it still has some issues with playback. Is there some setting within Quicktime that I can adjust to better play these files. (Same behavior occurs in VLC on the mac)

PS: My PC, with less power, is able to playback the 5d files in VLC without any stuttering.

I have a Mac Pro Octo-Core @3.0ghz w/10gigs of RAM and 8800GT video card. When I load up a 5DMkII video, the playback seems to skip every few seconds and even after transcoding it to XDCAM EX, it still has some issues with playback. Is there some setting within Quicktime that I can adjust to better play these files. (Same behavior occurs in VLC on the mac)

PS: My PC, with less power, is able to playback the 5d files in VLC without any stuttering.

I am on PC side, and have the same experience with fullscreen Quicktime play back. If I reduce size of playback screen, I can get a decent playback. VLC does playback well full screen, but much is sacrificed in terms of blocking and resolution.

We have to face it, processing required to playback the file is more than most of us have on board our systems. Remember, the processor has to rebuild each frame on playback because not all information is provided for each frame. In my case, I convert to Cineform intermediate files and playback is great in Windows Media player, and while editing in Vegas.

What version of OS and QT are you on? I know when OT 7.6 came out it helped smooth the video playback.

I can play back the files on a 15 inch 2.5 MBP fine, so I think it may be a driver issue with your graphics card. I remember reading somewhere about this before that there was a bug with specific Nvida cards and the 5D MKII video. I know they just released 10.5.8 yesterday, so I don't know if that would have any effect on your system.

But it is strange that the XDCAM EX versions are playing weird too. Also, if you are playing on the system drive, try a firewire drive or another drive on the mac. Your system drive may be slowing down.

If you are not getting smooth playback of the 5DII's raw .MOV on your rig then there is something very wrong as any modern Mac will normally handle them perfectly. As Chris notes Windows users do have problems with the native files & have to transcode them to an intermediate CODEC before they will play properly. This is not necessary on a Mac.

I have a similar but slightly slower system (Mac Pro Octo-Core @2.8ghz w/10gigs of RAM and ATI 2600 graphics) & that plays back at full 1920x1080 resolution perfectly smoothly at about 20% CPU utilisation (that's 20% of one core). These native 5DII files play perfectly smoothly on my MBP & my wife's white MacBook. They are all running 10.5.7 or 10.5.8 with the latest versions of QuickTime.

Is your disk full? The stuttering would be symptomatic of you having problems reading the file fast enough from the disk.

I've never had smooth full screen playback of native files on my 17" MBP (previous generation). There's always some stuttering - not drive related as it's the same from the internal drive or an external fw800 array. Running 10.5.7 with all updates. Once I convert to ProRes everything plays smoothly.

I got a $1800 AUD 17 inch PC laptop here.
Plays the raw 5D files no problems what so ever.
Edit with EDIUS no problems once converted to Canopus HO codec.
The raw 5D files nearly play back real time on the timeline but best to convert.
The laptop comes with twin internal drives so the files sit on the second drive and not system drive.