Design and Functionality
The second version of the Setsugen cooler is dramatically different from the first one. They modified just about everything, starting with the heatsink base and finishing with the fan:
The new cooling system measuring 176x33x139 mm and weighing 435 g consists of only 68 aluminum plates pierced by four copper heatpipes 6 mm in diameter. There is a 120x120x12 mm fan on top of it:
For added compactness of the cooler design the fan is pushed inside the heatsink, which reduces the effective cooling surface size of the latter substantially making it only 2,360 cm2. The heatsink plates are 0.25 mm thick and are spaced out at 1.3 mm from one another. These plates seem to be simply pressed against the heatpipes, because we saw no traces of soldering anywhere.
I would like to draw your attention to the peculiarity of the Scythe Setsugen 2 design, namely, to the fact that the heatpipes do not pierce the heatsink body evenly and are grouped in its lower part:
I dare suppose that the fan will not cool the heatsink too well in this area.
I was even more surprised to see how thick the cooler base plate was: 13 mm!
As you may understand with a base plate that thick the heat transfer between the heat source and the heatsink plate array leaves much to be desired. Moreover, there were no grooves of any kind where the heatpipes contact the base. However, there were a few in the top miniature heatsink, although they are hardly needed there. I would also like to add that the heatpipes are glued to the cooler base using thermal glue instead of soldering, which we would definitely prefer.
At the same time, we have to give Scythe due credit for making the base very even and finishing it nicely:
However, the base plate is only 30x29 mm big, which will be enough to completely cover the bare AMD Barts die and will be barely enough for AMD Cayman:
AMD "Barts" (Radeon HD 6870/6850)
AMD "Cayman" (Radeon HD 6970/6950)
The base of Scythe Setsugen 2 cooler will be too small for the majority of graphics processor heat-spreaders on Nvidia graphics accelerators, although they are all listed among the compatible products. Another (rhetorical) question is: do we really need to overlap the entire heat-spreader on these GPUs?
Scythe Setsugen 2 is equipped with a slim 12 mm Scythe Slip Stream Slim fan (SY1212SL12H-V), which we have already discussed in our Fan Roundup recently:
The “H-V” letters in the model name indicate that it is equipped with a variable rotation speed controller designed as a rear-panel bracket:
The fan itself is connected to the free three-pin connector on the mainboard. The fan rotation speed may vary in the interval from 800 (±30%) to 2000 (±10%), the airflow may vary between 19.4 and 45.47 CFM, and the noise – from 19.53 to 33.67 dBA. According to the results obtained during our fan tests, the thin Slip Stream model doesn’t look too convincing against the background of regular 25 mm models of 120 mm fans, in both: noise as well as airflow. However, in case of Scythe Setsugen 2 its job is simpler, because the heatsink to be cooled is only 10 mm thick, so a slim fan like that should be quite enough. Nevertheless we will check the cooling efficiency of Scythe Setsugen 2 also with a standard 120x120x25 mm fan. But before we proceed to the tests, I would only like to add that the fan is attached to the heatsink using two compact wire clips, which can also be used for a regular fan, unless it has bushes around the retention holes.