AMD A-series mobile. Performance/ AMD Turbo Core

Hello,

I'm considering getting a laptop for personal and school use, as well as gaming and for LANs. I am really interested in AMD's APUs, which give quite a lot of power for a very low cost; my budget is around $400.

I'm on Toshiba Direct building a Satellite L850D-BT2N22.
-The A6-4400M clocks at 2.7GHz with 3.2GHz using Turbo Core, but it only has a 1MB cache.
-The A8-4500M defaults to 1.9GHz and can Turbo to 2.8GHz and has a 4MB cache.
-The A10-4600M will put me too far over budget.

Does anyone know how to work this Turbo Core thing? Will the better GPU of the A8 make up for the slower speed? Is the extra 3MB in the cache going to make a big difference?

EDIT: I would naturally assume the A8, but the lower clock speed is disheartening and I haven't heard any good things about Turbo Core to make up for the low power. However, the GPU on the A8 is better than the A6.

Does anyone have solid information?