A small shroud sits over the middle of the heatsink to help guide the air over the fins, this shroud can be removed to give access to the fan
The base has been machine lapped, it's not perfect, but smooth enough for good contact with the CPU. The sample I received seemed to have been used before, this could explain the visible marks on the otherwise smooth copper base.Installation
From the goodies bag the following is needed to make the S² fit on S939/S754:
This custom bracket needs to be screwed tight onto the main board and into the back plate:
then you apply some thermal paste on the CPU and place the heatsink in the middle:
The clip is then used to secure the heatsink to the custom mounting bracket, it's a fairly easy process overall, it takes some time, but it's straightforward. In the photo below you can see the 4-pin connector the 92mm fan, on Intel platforms (and newer AMD motherboards) the extra PWM functionality is used to smoothly increase/decrease the fan speed automatically through the BIOS as the CPU temperature goes up/down. On the older K8 platform the 4th pin is not used. At the side of the heatsink (just above the mounting clip in the photo) you can see an arrow (====>) pointing in the direction of the airflow, you should install the S² so that hot air is pushed towards the rear of the case.
The installation bracket doesn't seem to allow rotate the S² in 90° steps, however taking a look at the motherboard compatibility list (.pdf)
reveals an additional AM2 bracket and a 90° "converter" to align the heatsink to blow hot air towards the back. However none of these extra features/brackets are mentioned on the product page
.Swapping the fan
It's certainly not rocket science, you only need the correct tools, the screws used to secure the metal shroud and fan have a custom head (much like "compaq"-screws) and thus can not be removed by your average + / - screwdriver.
once those screws are out, you slide out the 92mm led fan, and you can replace it with one of your own, for this review I've also tested the S² with my "reference" 92mm delta fan:
Onto our test setup ->