Disclaimer: I am slightly computer illiterate. You have been warned. Okay, so here's my story:
My old system was a 20" iMac which I bought in 2007. I had FCP 7 on it, with which I edited HD DSLR video from a Canon T2i transcoded to the Apple prores 422 codec. Everything was fine.
Then my new employer wanted me to start editing on Premiere Pro so that I wouldn't have to transcode footage. I tried this, and realized that my playback was painfully faulty, and would simply not play back for more than a few seconds before the image would freeze and the playhead would keep going. I decided that my problem must be my processor power, so I upgraded to an 8-core Mac Pro. Jumping back into Premiere, I realized that although my playback might have been a little (if at all) more smooth, it was still having the same problems it had on my old computer. So, great, $5000 spent on a new computer and the results are the same.
I then switched back to Final Cut and transcoding my footage to the prores. I expected my FCP experience on my Mac Pro to be faster and smoother than I could imagine, and yet I still had red bars at the top of my timeline telling me I need to render for something as simple as a cross dissolve. Worse still, oftentimes I couldn't even render, because I would get messages saying I am out of memory (I have 8 gigs of RAM), and other messages saying; "Codec not found. You may be using a compression type without the corresponding hardware card." WHAT?!
Weirdest of all, and I can't find an explanation for this anywhere, any time I try to change the speed of a clip, I am forced to render it, and upon doing so the clip plays back for about half a second and then just turns into black nothingness.
Please pardon my computer illiteracy, but I feel like I've just dropped $5000 on this machine for nothing. I'm just inches away from packing it up and going back to my 2007 iMac. Please help me understand what's wrong with Final Cut on this computer.
In FCP, look in the pop up menu in the timeline window upper left corner. Set the playback to be "unlimited". Be sure too that the sequence settings match the source material's properties exactly. Usually a new sequence will ask you to match that first clip's settings. so put any old clip in there that is the majority of the source material property wise, and say Yes to conform the sequence settings.
8-Core 3.0 Intel Mac Pro, Dual 2 gig G5, AJA Kona SD, AJA Kona 2, Huge Systems Array UL3D, AJA Io HD, 17" MBP, Matrox MXO2 with MAX - Cinema Displays I have a 22" that I paid 4k for still working. G4 with Kona SD card, and SCSI card.