Gaming on Atom?

I'm looking into purchasing a detachable tablet as my next full-time PC. I would like some recommendations if the Tribe doesn't mind about what to look at. I'll give a brief description of the type of device user I am. Current devices: -Nokia Lumia 900 -Xbox 360-Dell Latitude d830 running Windows 8 (five years old and near the end of its life) -Nook Primarily I do most of my gaming on my xbox, since my computer is running an intel chipset graphics card and hasn't been able to play a real game ever. I mostly use my computer for Office, browsing, and a little music. I used to watch video, but the cooling fans are malfunctioning and making loud noises (yes, I've cleaned them, but they're broken and not worth replacing), so I mostly watch video on my phone or xbox now. I know I could get most of what I want on an RT tablet or an Atom processor, but I've been trying to find out how well Atom works for gaming, because I would really like to play Civilization 5 on a tablet or ultrabook. Thus far, it seems Civ 5 will run okay, but not spectacular on current Ivy Bridge processors with Intel HD 4000, but I've seen no investigations thus far as to how well it works on any of the Atom processors. As it stands, I'm waiting to see how well the Surface Pro reviews, because none of the other PC manufacturers have advertised a detachable with an Ivy Bridge Processor in it. Thanks for your time.