You need to format it on you computer to FAT32, if you do it on your xbox most you can get is only 16GB I believe.

why not just make a folder called games in xex menu, on the 465g side and make folders inside that for each game. Then all you have to do is press x and copy dvd. keep the 15g for profiles or moving files from your computer or stock HDD to the 465g side (move filesto 15g using the xbox dash then load xex menu and cut ond paste them. hope this helps

Im pretty sure it will not work at all. I tried it and it wouldnt save my games because its not a HDD connected to the top.

The 14.9 can only be used by the NXE seeing as it's configured as a USB device (maximum possibly size being 16gb).
The rest of it can all be used through XeXMenu, Freestyle Dash or some of the many other applications for a Jtag.

I personally use the 16gb for all my save files, profiles and title updates (on the new dash), use my 360HDD for DLC and other larger files (seeing as it's a 120gb). Then with my USBHDD I use the rest of the 465 or whatever it is I have for all of my jtag programs, game rips, freestyle dash and whatever other goodies I wish.

EDIT: I just realised that I didn't clearly answer your question, so to answer it, it would come out of the 14.9.
Just rip your games using Freestyle Dash/XeXMenu and make a quickboot for them. It's far easier and leaves you with the 14.9 to use for whatever you want (plus I find that even though ISO's of your games are all 7 or so gigabites, many games are actually less than half of that size).