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What are the different enhancements the PS2 can make to PSX games?
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Two emulation options can be set in the PS2's main menu (hit triangle at the
Browser/System Configuration screen, then hit triangle again with PlayStation
Driver highlighted). One enables faster loading of PSX games utilizing the
PS2's 32X-speed CD drive (as opposed to the double-speed of the PSX); the
other filters textures on polygons to make them look "smoother".
Unlike the DVD and System Configuration options, the PSX emulation options
are not saved when the system is turned off, so they'll need to be reset each
time. This is not as bad as it sounds; since more than a few PSX games
function incorrectly with the options on, you wouldn't want to leave them on
all the time anyway.
How do these enhancements work?
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Fast loading is pretty obvious--the PS2 sends data to the RAM faster,
shortening some load times. However, some games are highly tuned to the
PSX's characteristic loading time, resulting in errors if this option is
enabled.
The texture smoothing process seems to be bilinear filtering. It helps
prevent pixellization when textures get up close (though it can still be seen
on particularly low-res textures), as well as correct aliasing in textures
(diagonal lines appear as such, instead of "stair-steps"). However, the
enhanced texture smoothness can sometimes throw the non-filtered actual edges
of the polygons into sharper relief; also, perspective correction is still
not performed, so the texture "warping" seen on the PSX continues to rear its
ugly head.
How well do these enhancements function?
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For games that work with the fast loading function, load times are typically
reduced by about 25% (e.g. from eight seconds to six), but results vary from
game to game.
Texture smoothing works best on games with a lot of texture-mapping
(obviously), like Vagrant Story or Final Fantasy IX. Games with software
filtering or heavy gouraud shading (e.g. Final Fantasy VII or any Crash
Bandicoot game) will show less or no improvement.
The smoothing often causes vertical "hairlines" in games that use 2D sprites;
the problem is especially pronounced when the sprites move against a 2D
background. It's highly recommended that you turn texture smoothing off for
pure 2D games like Castlevania and Silhouette Mirage. Finally, 2D-on-3D
hybrid games such as Strider 2 and Xenogears gain the most from texture
smoothing, as the characters are filtered as well as the environments, and
hairlines aren't as noticeable on the 3D backgrounds.
All in all, I find these "enhancements" very disappointing. Fast loading
seems to crash more games than it helps, and texture smoothing doesn't fix
texture warping, the PSX's biggest graphical shortcoming. There's good news,
though: the PlayStation driver is stored in firmware and could be updated via
a driver disc, much like Sony is doing with the DVD driver. So, maybe Sony
will release an updated PlayStation driver that enables better enhancements,
or a third party will cook a good one up.
http://www.gamefaqs.com/console/ps2/file/915821/9781