5DM3 material on FCP

Hi guys, I have an iMac 3,1 Ghz Core i5 with 12 GB og RAM. I have recently shot some 5DM3 material and have converted the files to ProRes 422(HQ) which I have read is the best setting for editing 5DM3 material. But FCP can't really cope with the material, my timeline settings are good, I'm editing from an external drive through firewire 800. What should I do? What is the best way to edit 5D material and still keep the best quality!?

Regards, Nicklas

Steve's right, use Standard ProRes. The Canon 5DMKIII is still highly compressed video files, there isn't really enough info there to warrant using HQ. I would bet that you won't see the difference between the two codecs. Standard ProRes will give you great quality, but without the file size and data rate of HQ.