No, double check it. Only the G4400 has the worse HD 510. The G4500 and G4520 have the identical HD 530 to the i3-6100 (even down to clockspeed).
As for performance, what makes you think they're much faster? Even the Haswell ones weren't that far off and from the few benchmarks I've seen Intel has halved the gap between them:
http://www.hardware.fr/articles/940-...ique-jeux.html
DDR4 for some reason doesn't seem much faster for IGPs than DDR3.
You don't need to spend money, it's very unlikely your memory won't run at 1.35V even if you have to bump it down a speed.