Well, he has
- Built-in graphics
- Enough power reserves to not overclocked to run like wild
but with appropriate cooling and good overclocking RAM can be quite rewarding.
Most BIOS 'likely inwischen opportunities for overclocking and for limiting the same offer. So if you want a quiet system as possible, so limited to the clock. Done. If you want to get the most out of his system, so there is the "K" more "room for improvement" and let him run.
This freedom are mMn the 10% price difference for non-K loose value.