Nx 70: Files are huge!

My Church recently purchased an NX 70 for the purpose of recording and online posting services. However there has been an issue with efficiency as the files seem to be very large coming in at about 10 gigs of only about 40 minutes of recorded time. This has made bringing files from the camera in to final cut almost a 5 hour process! We lowered the definition from HD to SD since the picture quality is still quite good, but it did nothing to the loading time of the files, and they were still very large. Does this seem like a computer processor issue, or is there another way to make the files smaller? We're running through either a macbook pro, or a 2 year old iMac, both which can usually handle HD files fairly well.