In common with most multi-platform projects, the disc layout is almost completely identical on all three systems. However, the amount of data dedicated to each section isn't. Dragon Age has two major directories: Modules and Packages. In terms of the audio elements, the Modules section appears to cover voice work, while the Packages covers game sounds: music and environmental audio. The "env" directory appears to consist of gameworld data, including those all-important textures.
Varying file-sizes between audio and environment assets across the console builds are difficult to reconcile with the final game, where these elements look and sound pretty much identical, but it demonstrates vividly just how much extra data the PC version possesses. It's a 16GB install in all.
We can expect the PC version's storage requirements to be pretty colossal, because it actually includes three different sets of textures and three different graphical quality settings. In an age where PC versions of cross-format games are held back by the technological limitations of the consoles, Dragon Age: Origins is a breath of fresh air.
Graphically speaking, it's much better than both console builds. Curiously, the PC version's .ini files even include resolution settings, suggesting that the textures on PS3 and Xbox 360 are just 25 per cent of the size compared to the PC build when it's running in "high" mode. As you can see from the comparison gallery, the cutbacks to texture quality on both console builds have been quite severe.
Let's re-run the initial console comparison video again, this time with the PC up against Xbox 360. If you fancy seeing the PS3 version compared with the PC build, we've got that covered too.
From the quality of the textures, it seems as though both console builds of Dragon Age: Origins are derived from a mixture of the "low" and "medium" settings on PC and there's actually little to indicate that the really high-quality assets from the computer version are present in the console game.
It also appears that the geometry levels are reduced in places on the PS3 and Xbox 360 versions. It's not often we see this, but the PC game is one of the few releases that supports multiple levels of detail in the 3D meshes (most multi-platform games simply stick with the console versions, with higher-resolution textures if you're lucky), and it seems clear that the "high" setting here isn't completely reproduced on the console versions.
The other bone of contention about Dragon Age: Origins has been audio quality. While it is likely that different compression schemes could account for the difference in file sizes, there's no escaping the fact that the PC version dedicates much more space to the sound than either of the console builds.
I can't say that this was a major issue for me but to give you some idea of the audio quality, here's a quick comparison video. It's the same section from all three builds, with all three captured from the respective Toslink digital outputs of each system. The audio encoding here was given 192kbps of bandwidth using the AAC codec in order to retain as much of the original quality as possible.
Perhaps there are better examples elsewhere within the game, but I can't say that the sound quality was that much of an issue. However, if you are sensitive to audio, I don't think the PS3 version offers that much of an advantage. The overall size of the game in terms of the amount of data occupying the disc is effectively identical to the Xbox 360 build, and there's no DTS or uncompressed audio support.
In summary, technologically speaking the PC original is the winner here. While the PS3 version is closer to it in many ways, it can't make up for the frame-rate and the cut-down visuals, and the lack of utilisation of the Blu-ray storage space is peculiar. For Xbox 360 owners, the visual downgrade is a touch more impactful, but the game is less prone to the PS3 code's frame-rate drops.
Dragon Age: Origins remains a strong game wherever you play it to a greater or lesser extent, but the PC really is the place to be. The user interface is stronger, it looks much prettier and it's much more fun to play. Failing that, the console conversions are about equal; their technical differences essentially cancel each other out.