Hey i recently built a rig with an a10 5800k, comes included with radeon 7660. I built this rig as a htpc to hook up to a new 1080p I got myself for the holidays. The only games i play is wow and sc2.
Now recently I read up on dual graphics on here where it showed it made an increase in fps with wow at 1080p resolution with good settings. I ordered all my stuff on newegg for black friday and i got a bunch of gift cards back totaling in 35 dollars.
Ever since I read up on it it kinda got me interested into getting a radeon 6670 for dual graphics so i can play 1080p on my tv.
Also some info i couldnt get a hold of is how the dual graphics affects memory. apparently the integrated gpu is 512 mb from the system ram with this card being a 2 gig make it a 2.5 gigs of graphics memory?
From what I've read on Dual Graphics, it's worth it for the FPS increase. I've seen tests double the FPS from adding the 6670 and crossfiring via Dual Graphics. WoW in particular seems to really benefit from this, so in your case I'd say worth it.
Not 100% sure about Dual Graphics, but the underlying concept is crossfiring, during which you don't add the RAM but rather each card uses its own. That's not exactly how it works, but that's the basics.
How this compares to the Dual Graphics system I'm not as sure. I'm going to assume you'll have the equivalent of 2 gigs but I don't know how the APU works with the dedicated card for memory purposes. Since the APU is only pulling 512 from the system RAM, your "total" might be less. That being said, either way you should be fine. At 1080p with a Dual Graphics setup, I don't see any problems with performance unless you really push it.