Hold your horses, problem was solved - connected the Noise to Bump instead, works beautifully and doesn't grind the machine to a halt.
Just posting this in case someone else comes across the same issue

Hi there folks,

I followed an extremely simple tutorial on how to create aanimated water texture using the noise and displacement nodes on a specular material, but I get absolutely no result in my render. Using Octane2020.
Would anyone here be kind and patient enough to explain my stupid soul what ...