Xzero, the guy that wrote a ton of shaders for Crysis 1, even fixing AF + POM, now that he works @Crytek says this
ou'd be amazed by how bad C1 is in terms of optimizations. You'd also be  amazed by how much merging shaders can help speed up the engine. CE2  was a huge waste of resources, it really was. Just.... trust me on that.
I hope you realize a lot of the shaders I wrote include several things  that are in the new engine, such as linear lighting or consistent  specular lighting. The lighting in CE3 is unarguably better and so the  console versions of C1 will also benefit. Don't underestimate physically  correct lighting and correct math.
Anyway, tetxures, objects, LODs, all of these things were not well  optimized for memory usage in CE2. With some correct optimizations they  could easily get the game to run within the consolelimits. Again, the  game was actually horribly optimized, and everyone at Crytek knows it.  Everything from the assets to the post-process pipeline wasn't given  much thought as they were purely PC at the time. The move to consoles  really opened their eyes to it. And now CE3 runs as smooth as butter. 
http://www.forum-3dcenter.org/vbulle...luebiggrin.gif
Though obviously draw distance and texture res might suffer a bit more,  but honestly the original game's textures were crap too. Most of them  are just 512x512 (some are even 256x256!) with some detail-bump mapping  applied. Most people have sugar-coated their memory of Crysis' textures.