The Heatsink Fan:
The Akasa AK-961's 90x90x25mm PWM fan spins at a speed of 500-3400RPM when controlled by the computer's BIOS, producing as much as 60 dBA according to our measurements. The fan draws power from a standard 4-pin PWM fan header and is internally illuminated by four blue LED's. The heatsink is backwards compatible with 3-pin power connectors, and in that situation the fan defaults to 3400RPM.

Heatsink Top:
With the fan removed from the center of the Akasa AK-961 heatsink, the construction of it's fins and heatpipes is clearly visible. The three 6mm diameter heatpipes overlap the base of the cooler completely so as much heat as possible is absorbed at the source. The heatpipes fan out to transfer the heat to different sections of the 0.3mm thin aluminum fins. The two outer heatpipes overlap areas which generally get the most airflow from the fan. The center heatpipe is half covered and half exposed to airflow from the fan. Each fin is spaced 1.2mm from the next. The copper heatpipes are soldered directly to the copper base plate, but not to the aluminum fins.

Heatsink Side A:
The body of the Akasa AK-961 heatsink stands 40mm tall, and the heatsink has an overall height of 71mm. The copper base appears to be ~3mm thick, and it is soldered to each of the three copper heatpipes. Note how the 90mm fan is suspended up side down from its motor over the heatsink - this is the same technique used on stock Intel reference heatsink fans.

Heatsink Side B:
From the side we can see the Akasa AK-961 heatsink is composed of about 50 aluminum fins of 93x38mm in size. The three heatpipes reach out from the base where they are closely located, and spread out through the body of the cooling fins to evenly distribute the heat. The impeller of the translucent blue fan is exposed on all sides. The joints between the copper heatpipes and aluminum fins are soldered, and do not appear to have any thermal joint enhancing compounds applied. The plastic clips lock directly into the 4mm motherboard mounting holes which surround the LGA775 processor socket. To release the heatsink from the board, the black portion of the clip is rotated 90 degrees and pulled upwards. The heatsink then pulls free of the motherboard.

Heatsink Base:
The copper base of the Akasa AK-961 heatsink measures 35 x 35mm in size. The heatsink comes with a pre-applied swatch of "hi-grade" Akasa AK-460 thermal compound. The copper base plate is pretty flat, and has a sanded finish. Surface roughness is on the order of ~63 microinches, which is considered satisfactory. The three 6mm diameter copper heatpipes are soldered to the base, but there are only compression joints between the heatpipes and aluminum fins.