What has that to do with it? I used the filesystem example with regard to efficiency. The 360 isn't very efficient with regard to disc capacity...

But are you thinking of a proprietary filesystem or simply of a reserved part of the file hierarchy?

I think some of that space might be generally empty, but is also reserved for system stuff like OS patches. Didn't we learn some time ago that some new 360 game will require NXE and include the patch to update to that version of the system software for people with no access to the net?

Update

Google was my friend: apparently it uses a proprietary FS (xboxdvdfs), a minor variation of the original xbox one

Maybe you remember writing "The 360 can thus store well over 20% less game data on DVD than a PS2."

(I'm pretty used to your "memory lapses" already)

First of all, 6.8 GB is exactly 20% less than 8.5 GB, not "well over 20%". Second, feel free to do a PS2 vs 360 comparison but then take everything into account since I'm pretty sure some space is also used for non-game data on PS2 discs.

Who cares? We're in the consoles 4th year, multi-disc games rank at a mere half-a dozen (all exclusive so far) and the 360 still performs better for cross platform games by ever increasing margins.

I'd say the disc space relevance for games has been settled, stick to retail movies.

I mean it could include the filesystem, firmware/dashboard updates (for several regions as some games are region-free), DRM and who knows what else (probably including empty space as well, I agree)...

I just found some install times:

http://www.gamespot.com/hardware/blogs/hardware-insider/909185655/26656232/xbox-360-hard-drive-game-installation-testing.html

NBA Live 09: 6.3 GB in 9m7s (or 11.8 MB/s)
The Force Unleashed: 6.6 GB in 9m47s (or 11.51 MB/s)

the 360's dvd data limit is not 6.8gb

@ NJ5

I already removed that question, as I realized that copying a DVD only involves one layer switch (which makes sense if you want to copy a lot of data in one go, but is not practical for a game) and there are several different DVD drives used in 360s and of course developers have to take into account worst case scenarios for developing their games.

@nikkom

I think the information on the BluRay discs are not optimized, hence the mandatory install. Especially seeing as how those games are ports, it could be cheaper just to have the install than to reorder all the information.

But notice the 15 MB throughput figure, is just PR regarding max speed. Even when copying a DVD onto the harddrive layer by layer you wouldn't reach this on average as NJ5 pointed out.