For the fastest resolution for 99.9% of older machines.
640x480 @ 16bit still performs very well.
Overall, 16bit and 32bit colour depth will be supported just fine. 24bit is pretty much gone these days as far as accelerated support. Old 3DFX users (pre voodoo 4) dont have accelerated support above 16bit. Not sure if thats an issue these days but I guess it depends on your target audience (why loose a potential sale or two as an independant?. Every sale counts).
Personally I'd stick to 640x480 @ 16bit / 60hz as a default and work up via that from an in game menu. That way you're pretty much guaranteed to work fine for the range of old to new machines.
640x480 @ 16bit still performs very well.
Overall, 16bit and 32bit colour depth will be supported just fine. 24bit is pretty much gone these days as far as accelerated support. Old 3DFX users (pre voodoo 4) dont have accelerated support above 16bit. Not sure if thats an issue these days but I guess it depends on your target audience (why loose a potential sale or two as an independant?. Every sale counts).
Personally I'd stick to 640x480 @ 16bit / 60hz as a default and work up via that from an in game menu. That way you're pretty much guaranteed to work fine for the range of old to new machines.