The integrated HD 6520G in the Llano A6 3420M is a little more powerful than the Intel HD 3000 graphics core. However, the CPU core of the A6 3420M is nowhere near as powerful has the Core i7-2630QM. Most games are not CPU bound so playing most games should be better with the A6 3420M.
In terms of overall GPU performance, the Intel HD 3000 is basically the same as a desktop Radeon HD 5450. The HD 6520G is slightly more powerful than the desktop Radeon HD 5550.
In terms of CPU power, if both A6 3520M and Core i7-2630QM were clocked at the same speed, the Core i7 would have roughly 25% more performance.