I have FCP6 running on a Mac Pro with 2x2.66 GHz Dual Core Intel Xeon processor, with 5GB of RAM. I upgraded to Lion and now FCP gets the spinning rainbow nearly every 5 minutes during operation. So does Squeeze 4.5. It is unbelievable difficult to work now.
Not sure what to do. Do I get a RAM upgrade? If so how much? Or do I need a new computer. This is really unfortunate. I wish there was some upgrade warning. I wouldn't have done it.
Your computer is underpowered as far as RAM is concerned, but I dont think that the root of the problem. RAM usage is not significantly different from Snow Leopard with Lion. More likely something got corrupted when you upgraded, so if you were good before, you should be ok now.
Boot from your recovery partition, run Disk Utility, repair permissions. see where that gets you. You may have to reinstall Lion.
This forum has been repeatedly warning people for years not to do an OS upgrade on a FCP install. Recommended is a new drive, clean OS install then a new install of FCP and other software. That way if something goes wrong, you can pop the old drive back in or have it set to dual boot.
Lion and FCP6 is not a recommended match anyway as installing FCP6 on Lion is difficult. If you can go back to your previous OS and working FCP install then that is best.
Searching this forum to prevent common problems like this is much better than searching or asking for a fix later.