Nope, tRFC. It gets set differently at higher and lower RAM speeds and decides your RAM/IMC/HT ref. stability. Keeping a high tRFC gets you best HT ref. maximum speeds, I've mentioned it since early December just because of this reason because users will get a low HT ref. and say "that's it" whilst it was their settings which were holding back the HT ref. mainly.

My old CPU-Z files which I hadn't verified till yesterday (v1.42) don't verify anymore.

Ganged mode is single channel.