What is AMD Apu a8 3870k maximum amount of video memory?

32mb to 512mb max for UMA {Dedicated from system ram} and another 3.5gb (I think) of hyper memory {Shared from system ram} which is slightly slower than UMA because of the extra layers of management involved between the driver and windows memeory management which UMA does not need to go thru.

edit - the hypermemory is assigned as needed thru windows whereas the UMA is subtracted right on bootup and never available to windows.

Be sure to get 1866 speed memory for best performance.

Thanks for your reply. I've searched everywhere but I couldn't find this piece of information.
So how is UMA memory assigned for video purposes? I mean, is there something influencing whether to reserve 32mb or 512mb for video dedicated memory? Or does it depend on mobo's model?

So, as you say, you can have up to 4 gigs video memory, when needed of course, but speed depends on memory frequency, so I guess this difference in speed (1333, 1600, 1866) is more relevant now that it's used and influences video performances