Increasing the RAM will decrease Cycles time rendering?

I got 24 GB ram on my system and I work with Cycles for some Archviz render with gazillions of polys.
I don´t know whether increasing ram to 64 GB will yield any speed result in Cycle’s rendering.
I always render in 2K but sometimes the 4K render take (obviously) more time.

Any help will be appreciated.

Unless you are going into swap, the only way a new set of RAM will increase your speeds is if the new kit has a higher clock.

Even then, the higher clock will only give you a boost of a few percentage points at most and that is assuming you have a recent AMD system.