I've got a few computers but the one that I use for working with D800 images is an iMac 27 inch screen about three years old with 4GB Ram. I can input images from SD cards straight through the side slot built into the Mac but for CF cards I use a separate card reader and this is where I am struggling. First thing, transferring images is very, very slow whether it is from SD or CF card. I've tried twice in the last few days to transfer images from a 32GB San Disk CF card even leaving the Mac on for twelve hours overnight and the transfer had failed when I checked in the morning. I had to force quit iPhoto, which I normally use to import and sort out the ones that I want to keep from there. Tried again last night, same as before the images were transferring taking about 8-10 seconds per raw image to transfer. I sat and watched it for a while and it seemed to be working okay until about 2/3 of the way through. Then I noticed that the icon showing the D800 card was no longer present on the left of the iPhoto screen and that the transfer had jammed again. I force quit iPhoto once again and intend to have another try tonight, maybe importing in smaller sections according to what day the images were taken. Just wondering if the issue is software with iPhoto or some issue with the card itself. The card was bought new when I got my D800 in May. The strange thing about this CF card compared to its equivalent SD cards also by San Disk is that the CF card always seems able to take a lot more images on it, maybe 600 to 700, whereas the 32GB SD cards are usually about 400 raw images per card. I had assumed that the actual storage capacity would be the same with each format. I only bought one CF card and have three virtually identical San Disk 32GB SD cards in addition. I only set the camera to use the CF card first as image transfer seemed fractionally faster than the SD cards but I think in future I will use the SD card slot as the main one. Without another CF card to compare it with, it does leave me wondering whether there is something wrong with the card that I have.