Uh...lemme calculate it...assuming that we are talking about original versions (so FF 1-3 for NES, 4-6 on SNES etc):
FF 1 thru 6 could fit in N64 cart so that's not much.
FF VII was on 3 CD...let's say that's about 2 GB of data.
FF VIII and IX were on 4 CDs...2,5 GB each for simplicity so that's 5 GB.
FF X, X-2 and XII required 1 DVD each...let's say 3 GB avarage so that's 9 GB.
9GB+5GB+2GB+several MB=16GB with several MB
There's still more than enough room for FF XI (I dunno how much does it "weight", but I don't think it has more than 9 GB of data) and few other games like FFT.








