AlienALX
Well-known member
I think it'd be an optional thing, even if you don't use all that current(~235W for 8-pin, ~150W for 4 pin), spreading the load out across several cables reduces resistance and voltage drop/power loss which can get quite significant at 12V with higher currents(I^2 losses so they increase exponentially), which would result in slightly lower pin temperatures, better efficiency and better stability.
It could be for the memory or PCIE lanes tbh. With 4000mhz+ on the table that may need some voltage. I had a 8+4 pin board once (CH AM3) and it used the 4 pin for the memory. Then again there may be a connector elsewhere for the PCIE etc.