Different Types of Workspaces - PPU Settings?

Hi

I'm trying to setup PPU for my workspace, but it appears there are different types of workspaces.....   See below for comparrison:

One I have created, and it has a setting section, where I can selsect the Capacity as PPU 

Another one, where this option does not appear:

I can't seem to figure out how they are different, and how I enable PPU for this workspace.  Can anyone point me in the right direction?

Robbie