Not sure if this is the right forum for this but lets give it a whirl.  The models in the image are low poly game models from World of Warcraft.  They are identical in poly count, and from what I can tell textures.  The one on the right looks smooth however while the other is jagged.  Opening the material room on the guy on the left isntantly makes him look like the right.  Also rendering them they both look jagged.  Does anyone have an idea why this is?  Thanks for any help.

The size of the texture map will make a difference. The UV map will determine the resolution for an area, and the size of the image map (in pixels) will determine how smooth or jaggy it looks.

Of course the final image size of the render will determine how smooth or jaggy any texture looks.