OCWorkbench has posted a preview on the Gigabyte 3D Cooler-ULTRA PCU 31-SD heatsink

This new heatsink has no adjustable fan speed knob. Instead, a fan control cable can be attached to reduce the fan speed to 1900RPM versus the 2500RPM by default. The previous Cooler-Pro can run from 2000 ~ 4000 RPM adjustable whereas Cooler-Ultra is stuck at either 1900 or 2500. That is probably why the noise level drops to 18.5 dBA at 1900rpm and 23.7dBA at 2500rpm.

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