The SI-128SE is similar to the original SI-120. They share the same overall design, with a copper base connected to a large array of aluminum fins via multiple heatpipes. Since the fins are not directly attached to the base, additional support is provided by two stiff sections of wire that connect the fins to the base on the side opposite the heatpipes. Speaking of heatpipes, the SI-128SE only uses four as opposed to the SI-120's five, however the diameter has been increased to 8mm. The finned section has also grown, both in size and number of fins, and the only visual difference between the SI-128 and SI-128SE is the addition of thru-holes in the sides of the fins, a design copied over from the HR line of silent tower coolers. The SI-128SE weighs in at 510g, which falls somewhere in the middle of the smaller 92mm coolers and the larger 120mm towers.
A closeup of the base shows that it is actually constructed of two pieces, a nickel-plated copper bottom and an aluminum top cap, with the four heatpipes sandwiched in between. The base has been left with a ridged, machined surface that does not cast a good reflection. Every Thermalright heatsink I've seen has had the same finish. Thermalright must feel that polishing this smooth does not add any appreciable cooling ability.
Two rubber anti-vibration strips are included. These adhere to the top edge of the heatsink fins and help to hold a 120mm fan in place without slipping and also provide a cushion to inhibit noise and vibration. A fan is not provided but any 120mm fan should fit just fine. Thermalright suggests a standard quiet 120x25mm case fan, however thicker, high-volume fans would work well too since the fan clips attach to the bottom lip of the fan. Like many of Thermalright's heatsinks, fans that have enclosed mounting holes or solid frames will not work with the clips provided. The fan I'll be using with the SI-128SE is pretty typical as far as 120mm case fans go, rated for 63cfm at 29dB. This provides a good balance between airflow and noise, and should have little difficulty in outperforming the stock AMD cooler.
Next up, installation.