Iris Pro 5200 or Iris 5100?

Hi All,

I'm going to buy a new Macbook Pro tonight. I'm torn between the 13" and 15" models, purely because I want to be able to play some basic games on the move (Starcraft, WoW, Bioshock infinite, other steam games).

Is there really much difference in practice between the 5200 and 5100 integrated graphics? I understand the technical differences with the 5200 essentially being the same, but including a extra 128mb of memory cache, but does this actually translate to a IRL benefit?

For clarification, I'm only interested in the integrated graphics for playing basic games on the move at low settings. I do not do any image/video editing or rendering on my portable devices. That's reserved for my desktop.

Thanks for any help!