DDC/CI stands for Display Data Channel Command Interface and basically allows monitor control via the graphics card. This is not like the software methods in your GPU control panel that just darken/brighten the image.
thx all for replies. like i supposed people prefer d5 over ddc,more silent,more reliable (have found more topics about faulty ddc than d5).
A black impeller in the DDC-1 series pump. One other item to note, the blue impeller has a different magnetic field than the black impeller since the blue impeller is to run in an 18W rated pump. So, don't fully blame that all DDC-1 or a DDC-1T pumps are always noisy like yours. If you can find a black impeller, swap it into your pump.
I'm just wondering though if the DDC motor magnets don't hold the rotor up, or is there a chance the the rotor can fall and impact the pump housing? I'm curious because mounting it with the motor pointing up, works a lot better for my build than mounting it with it pointing down.
I have three DDC 3.1 PWM pump/res combos (2 EK, 1 Bykski), no issues, the oldest has been going over 3 years in a system with 2 rads, CPU and GPU. It is not silent but I would not say it was noisy, once the system gets loaded and up to temp the fans are louder, when the system is idle you can hear the pump.
DDC-1Ts growl when undervolted from my experience. If you have a friend w/ one and you ok w/ its noise then you aren't as worried about noise as much as I suspected. Even a dampened DDC-1T is unbearable to me. Queen of Dreams. 2P Home Server. OG Stacker 830. WIP. Big Lian Li. MOTM Jan 2015. Updated Mar 2016. COMPLETEDForever Alone FT02BW.