My main camera creates 22.3MP files. Each RAW is around 25-30MB. I use a 2009 iMac, and it is fine to work on. It is definitely not blazing fast, but it gets the job done. I download my images through Lightroom 4, so it converts to DNG, then creates a set of standard previews for all. That takes somewhere around 15 minutes or so when I download an 8MB card that is full. I use a card reader.
And I think you would need to check into the specs of the camera. My main camera has the option of full-size, medium or small RAW files.