Best practices/performance - 2 Atlases Versus 1 if space is left

[IIIHAPPYIII]

I have a question on performance and best practices. I have an atlas that I am needing to add a few more pngs to and it will bump it from 1024x512 to 1024x1024. This will cause a lot of empty space on the atlas. Would there be a substantial enough performance gain by placing those pngs on a separate atlas? This would create a 1024x512 and a 512x256 atlas'. For mobile devices.

Thanks

[ArenMook]

No, there would be no performance gain. Quite the opposite actually. One texture is always better than several.