It's been widely reported to be a near-filled 50GB disc, so I won't even talk further on that topic except to remind people that the Japanese voices were to be included but were not because of space issues. I would have enjoyed that.

Now, my main point...

It should be a bannable offense at this point for you to make these comments about read/seek times. I'm pretty sure I have corrected you in several threads before and so have other people. Let's get the truth out there once again...

single layer dvd on 360 (12x read speeds) is only faster than blu-ray at a certain part of the disc. Things that need to be loaded faster go there. The blu-ray drive on the PS3 is faster, uniformly, than DL-DVDs on 360.

Installs to hard drive are, of course, even faster. There is no need for redundancy, and it certainly wouldn't take tripling or quadrupling of the data. I understand that Bethesda said they did that, but that is not the only reason load times were twice as fast on the PS3 for Oblivion. Even if redundacy is used, isn't that a great reason to have all of that space? Blu-ray is already faster than the 360 DL discs, so having more space just adds to the advantage.

Regarding processing power, I don't believe we can say the 360 can't run the game... There are games with great graphics running at 60 fps on the 360 (e.g. Ninja Gaiden 2), while MGS4 only requires 30 fps. Going by the information posted by Quaz51, and taking into account the framerate differences, NG2 is actually calculating 66% more pixels per second than MGS4, which means even if MGS4 graphics are much more demanding in other areas (texturing, polygons etc), there's room left for graphical improvement by having the framerate at 30 fps. Of course, there are many unknowns here, but my point is that it's certainly not proven that the 360 couldn't handle MGS4 graphically.

Regarding disc space, we can't ignore the uncompressed audio element. It's unnecessary for the vast majority of people, who have neither the ears nor the audio hardware necessary to notice the difference between well compressed audio and uncompressed audio. I'm pretty sure that if Konami was having difficulties with cramming MGS4 onto the Blu-Ray disc, audio would have been one of the first things to be compressed (even if with a lossless compression algorithm like FLAC which can halve the size of audio files with no loss of quality at all).

Being a software engineer, I can tell you one thing - it's rare for developers working in a professional context to optimize things which don't need to be optimized. I believe Konami wasn't space constrained with this game, having 50 GB to work with they took a lot of liberties like using uncompressed audio. If Konami is interested in porting it to the 360, they'll have a reason to optimize for lower space, at which point they can drastically reduce the size of the game data (most likely, starting with the audio as I said).

After reducing the size of the game data, in a game of this genre it's not hard to split the game between several discs (I'd venture the guess that no more than 3 double layer DVDs would be necessary). It's not an open game like GTA4 in which you can quickly go anywhere in the game. As many have said, it would actually be less painful for users to switch discs than to endure the multiple installations which the PS3 game requires.

Make no mistake - I'm not saying it would be a cakewalk to port this game. It's a big production, a huge project, and there are certainly a lot of things which would need to be done in order to convert it to any other platform. What I am saying is that, looking at the big picture, it's not implausible at all that this game can be ported to the 360. All the people I've seen attempting to prove otherwise are relying on unproven assumptions which only Konami itself can judge. Of all the publicly available information about this game, I have seen nothing which automatically proves the technical impossibility of a 360 port.

The Blu-Ray specification states 1x speed is equal to 36Mbps, which makes 2x Blu-ray 72Mbps. http://www.blu-ray.com/faq/#bluray_speed

The dvd specification states 1x speed approx 10.5Mbps, or126 Mbps for a 12x DVD drive.

http://en.wikipedia.org/wiki/Dvd

Now as you pointed out previously, the Blu-Ray speed is constant wheras the DVD9 speed fluctuates. But you should understand that talented devs can and will place all high-priority data in the fastest parts of the disk. So commonly used textures that have to be doubled or tripled up on a Blu-Ray disk when 72Mbps is insufficient can be put on a DVD9 just once if they are placed on a part of the disk that reads at 7-12x, depending on what speed is needed.

As for seek times, 12x DVD drive seem to be in the 100ms-120ms range, while 2x Blu Ray is around 350ms. I'll try to find a link for that some time soon. But as you can see, the DVD is substantially faster. If faster Blu-Ray drives were available when the PS3 was designed, this would be a moot argument, but they weren't, so it isn't.

Whilst you are technically correct in pointing out the Blu-Ray drive is just barely faster "uniformly" (by which I assume you mean on average) than the DVD9, this is blatantly deceptive because no dev worth their salt will put important data that needs to be regularly retrieved on the slow part of a disk.

We have seen time and time again that most installs are not optional, they are necessary, because the Blu-Ray drive places a severe limitation on the Cell (and perhaps the RSX, though it isn't that powerful) without a compulsory install for regurly retreived data. To deal with the lower seek time, devs have to duplicate data on the Blu-Ray disk. In this regard, the Blu-Ray drive both creates and solves its own problem, but it does so whilst adding a substantial cost to the system.

There's a lot of false assumptions made in this thread about installs.

Some 360 SKUs have no HDD so the game would have to be made to support this.

If you go the way of several discs ( which would be a necessity for the 360) you're going to have to replicate a lot of information on each discs, because you can't write it on the HDD. A lot of the graphics and stuff is the same accross every act. On PS3 that stuff only has to be once on the Blue Ray.

If you go the way of several discs you suddenly have to replicate that data on every disc and that reduces a lot the amount of new data you can put on every disc.

I have no clue how much size that data is but it could easilly reach 1Gb.

Second assumption is that a Dual Layer DVD for the 360 is 8.54 Gb, there is only 7Gb useable for game content on a 360 DVD ( Google, it, wikipedia search it, it's easy to verify). So lets do the maths now :

7 Gb per disc : 31.5Gb total : 5 discs.

Factor the data that has to be replicated on every disc ( lets guess 1 Gb) and you now have 6 discs...

That's about double than what has been speculated on this thread...

The 360's drive slows to 3.3X speeds, your information with regard to read speeds and seektimes are misleading:

"For really old Blu-Ray drives (like 3 years ago). The PS3 uses a fairly compact triple wavelength OPU.

From my own personal experience testing a Sony BD-RE drive (actually uses a Panasonic drive mechanism) and a Hitachi-LG drive of similar specs, for similar sized data sets the BD drive typically has almost the same if not significantly faster random seek times. That's generally because data sets between 4-8GB span the entire disc for for DVD-ROM while only covering a third of a BD-ROM, so on average a BD-ROM is going to have seek times in the range 50-100ms with a worst case scenario of around 200-230ms. The DVD-ROM drive will average between 110-150ms with a worst case scenario of around 170-230ms.

Of course once you start getting into larger data sets that that Blu-Ray can handle the average and worst case scenarios (which is an entire disc sweep which takes around 350-400ms) will eclipse the worst case conditions on a DVD-ROM. That being said, even with 23+GB of data with a 100 randomly generate seek sectors I still get around 100ms on average. Besides, if you find the need to randomly jump around to random sectors greater than 4GB in span, then your title has bigger issues than the capabilities of the drive."

http://forum.beyond3d.com/showthread.php?t=42157&highlight=speed&page=2

"2x Blu-ray Drive (72Mbps(9MB/s))
Single Layer (2http://www.neogaf.com/forum/newreply.php?do=newreply&p=10460097
NeoGAF - Reply to Topicx CLV) - Constant Linear Velocity (Same speed across entire disk)
Double Layer - Couldn't find any data but no games have been released on a double layer yet.

Entire Blu-ray Disk is read at 9MB/s.

12x DVD-Rom Drive SL (9.25MB/S-15.85MB/s(AVG ~8x(10.57MB/s) DL (4.36MB/s-10.57MB/s(AVG ~6x(7.93MB/s)
SL(DVD-5) 12x Max (5-12x Full CAV) - Constant Angular Velocity (Speed Varies from edge to edge)
DL(DVD-9) 8x Max (3.3-8x Full CAV) - Constant Angular Velocity (Speed Varies from edge to edge)

SL DVD is 1.57MB/s > SL Blu-ray
DL DVD is 1.07MB/s < SL Blu-ray

Majority of 360 games are on DVD-9."

http://forum.beyond3d.com/showthread.php?t=42157

What this means that overall the PS3's Blu-Ray drive is technically faster, combined with a default harddrive there's no contest, as the part where the 360 can read a DVD slighly faster can easily fit on a harddrive.

Games optimised for either Blu-Ray disc or DVD can pose problems with regard to a potential porting process. If optimised for constant streaming speeds, you will have to work around this, for instance by streaming less high quality audio and graphics.