On the FX platform the best way to overclock is through the NB the guide states it as well. It will get more performance and use less power. These CPUs were very good in high end motherboards where you could put 32gb at 1866mhz or higher and raise the nb and htlink at 2400 or higher. And if you had good cooling on air you coul get it to 4.2-4.3mhz more or less in a stable way. You could get it higher but you dont gain too much and the temps get too high which might degrade the chip.

If you over clock only the cpu clock you will get higher temps and not as much a performance boost. The FX platform loves memory speeds similar to ryzen even though it doesnt have infinity fabric you can test it out with 2 sticks at 1600 for a few weeks and then test at 1866 and you will notice the difference. You wont need a software telling you the FPS. Its very noticeable. And if I'm not mistaken the CPU runs best at 1866mhz or higher. But that is the sweet spot.