What are the optimal system requirements for TRL NEXT GEN?

[Treeble]

I hope to buy a new computer by the beginning of next year and wanted to plan ahead so I can know how much it'll cost etc. I've looked about and only found optimal system requirements for current gen, and even though my brother's computer meets them all, the game still runs at 30fps when playing in 1024x768. I wanted to be able to use higher resolutions at a smoother framerate (60fps or more would be ideal, of course) and use next gen effects.

What sort of system requirements are needed for that?