NH-U12P y-split cable

[Miek]

For my build (I'll be ordering parts within the next couple of days ) I plan on using the Noctua NH-U12P. It includes a y-split cable so that both fans can run off of the CPU_FAN plug.

 

Would using the y-split cable reduce cooling performance? In one of the videos I watched, it was claimed that while using the y-split cable and no low noise adapters at all, the fans were only running at ~300RPM...?