USB drive/s?

Can my 360 slim make use of 16GB USB drives total or in each USB slot. Just wondered becasue I stuck both in, they formatted correctly and met all specifications, however on the memory panel it shows only 14.4 GB total available, but I have 3.2 GB onboard, 14.3 on one USB and 14.4 on the other USB. Individually they all seem to show and work when selected, but collectively the total 32 GB just doesn't reflect acurately. Is this just a quirk or what?

- Exterminate... EXTERMINATE!!!

I was under the impression that you could only have a max of 16GB. You could have 2 8GB's or 1 16GB... Could be wrong