How are HT link, NB frequencies linked to FSB?

gilgameshflood · November 28, 2014

While overclocking my FX 8350 via multiplier I can reach up to 4.6GHz max on my chip. NB frequency is 2200MHz and HT link speed 2600MHz.
I wanted to try out 4.6 on FSB overclocking but I couldn't get even a 4.2 overclock.
This is all I know:

1) CPU multiplier x FSB = Your CPU clock speed. So if I want 4.2GHz I need to set CPU multiplier to x20 and FSB to 210. I keep x20 because that's what most people use.
2) The NB and HT link speeds should be same or lesser than the default frequencies(in my case NB 2200MHz, HT link 2600MHz).
3) RAM can be same or lesser frequency than my max supported frequency. Mine is 1600MHz.

The last two steps I just made up because I couldn't find anything about the ratio in which they are linked to FSB(which is why I'm asking).

And I tried everything I can to get it stable at 4.2 and failed- Bump up voltage, step down a bit on LLC, Try different NB, HT, FBS, RAM frequencies.

UPDATE1: Also the ram frequency, how is it linked? Now I just know the multiplier and FSB relation.

FlanK3r · November 28, 2014

your CPU has unlock multiplier, so more easy way is use 200 FSB (auto) and 23 multiplier ,-).

harrynowl · November 28, 2014

Well they're on a multiplier of their own. At stock on 990FX it should be x12 on both (2400).

Say you raised your bus speed to 220 that's 2640. When you go higher you can reach instability. Either drop the multiplier to keep ~2400 or, as noted. The FX series are unlocked so it's easier to just leave it alone entirely.