You'll want 2 sticks of RAM to run in dual channel mode, or you're going to kill the graphics performance. I looked at single channel v. dual channel memory in
my A6-3670k review - the performance difference in games between 2x 2GB and 1x 4GB was 20% - 30%. The A10-5700 has an even faster GPU, so it gets even more bandwidth starved, which means you'll see even more improvement, just by using 2 sticks of memory instead of one.
Ideally, you want dual channel 1866+:
http://www.novatech.co.uk/products/c...dt1tx0ceu.html - 2x 4GB normal profile kit £45
http://www.novatech.co.uk/products/c...e1tx0ceu..html - 2x 4GB high profile heatsinks £41
But a dual channel 1600MHz kit would be better than one stick:
http://www.novatech.co.uk/products/c...ds1s00ceu.html - 2x 2GB normal profile £23
Unfortunately 4GB kits of 1866+ memory are in short supply and cost almost as much as 8GB kits...
The faster the memory you put in the build, the better the graphics will perform. The hexus lads did
a great Trinity memory scaling review which you really should read - even going from 1600MHz to 1866MHz can yield 5% - 10% performance increase. One stick of 1600MHz RAM is going to kill the benefit of using a trinity APU...