Well, it depends. How much ram is reserved for other apps in the settings? On my machine it is 3 Gb not a ton but I also have a total of 24 Gb. That said what is the issue your having? long render times, slowdowns, what? The A8 is not all that powerful for video editing either. Intel chips are much better suited for that.
Intel Core i7 2700k (4.8 @ 100x48) Watercooled - 16GB Crucial Ballistix @ 1600 Mhz 188.8.131.52 2T
8GB Corsair Vengeance @ 1600 Mhz 184.108.40.206 2T - Asus Sabertooth P67 - Asus Radeon 7970 Ref. (Non Ghz)
Heatkiller 79xx Ni-Bl (Soon) @ 1050/1500 - 64Gb Crucial M4 SSD - 3x Hitachi 1Tb - Corsair TX950W
Azza Genesis 9000B - 2x Samsung SyncMaster S27A550H - Vizio 32" LCD