Mac Pro video issues

Recently got a Mac Pro 2.26Ghz Quad Core with 8gb Memory, Nvidia GT 120, 512 Vram. It came with Snow Leopard and I did the upgrade to 10.6.1 when it came available. Running Final Cut 7.0.1

Starting working with footage from EX-3 720p60 (35mbps) and noticed that stuttering on playback was constant. Inside FCP, in QT, in spotlight preview. Thought that this might be a Snow Leopard issue so set up a boot drive with Leopard on it. Stuttering remained. Doing a pan across a table it would jump constantly.

Starting trying it on different drives; internal drive just for media, external FW 400, external FW 800, same stutter, same spots. If it is the same spot instead of random thought maybe it was the card in the camera. Plays back in camera fine.

Next thought maybe its the new machine, took file home to iMac with Snow Leopard and FCP2. Same stutter. Thought it's got to be the recording.

Put it in a Power PC G5 on external RAID and no stutter. This machine is on FCP 6.0.6 and QT 7.6.1 Put it on a 2nd Power PC G5, same specs, no stutter. This drive was just an internal 7200rpm drive used for DV. Played clean in FCP, QT and Spotlight preview.

Took the external RAID that worked on the G5 and connected it to new PowerMac and the footage stuttered. So at this point I'm leaning towards an issue with new machine. Is NVIDIA GT 120 the problem, although I don't think graphics card determines FCP playback?

Permissions, preferences have been trashed, disks verified. Read speed from FW400 36.8Mbps, FW800 74Mbps, RAID 43Mbps, Internal 120Mbps. All higher than 35Mbps of file so think they should be fine?

Can anyone suggest any other options to check?

Thanks



Jim McNally
The Commercial Factory
www.commercialfactory.com