FAN DESIGN


The Scythe Slip Stream “Twelve Winds” 800 rpm fan, AKA Scythe Slip Stream Kaze Jyuni model SY1225SL12L is a Sleeve Bearing, 9 bladed 120mm fan that rotates at a nominal 800RPM. At this extremely slow speed it generates an impressive 40.17CFM airflow, and best of all does it while making nothing more than a low tonal hum.

The fan exhibited very little shaft “slop” or forwards and backwards motion to the fan blade assembly and felt very tight. More importantly, the fan displayed no angular slop when pushed/tapped on only one side of the fan. This combination makes for a fan that is very tight and even as it’s sleeved bearing ages, will still be useful for a long time to come.

One thing that is not immediately obvious is the fact this fan has an extremely small diameter engine hub or rotor housing. This decreased hub means that it has a much smaller dead zone where no air is being moved. This is a very desirable feature to have in a CPU heatsink cooling fan as the smaller the area that is not properly cooled the higher the thermal efficiency of the unit. Another interesting thing about this fan is the fact that it uses the older style 3 pin fan header. It is understandable why this was done since this fan is designed to run at one speed only and unless you are a silent PC fanatic, reducing its noise levels via fan speed control is not needed.

The Kaze was very quiet and didn’t create many vibrations; of course I would have been very surprised if it did as this fan is only spinning at a claimed 800rpms. When installed in a CoolerMaster CM 690 case the Kaze fan was not audible over any of the Scythe E’s which were previously installed into the case. This is a laudable accomplishment that few CPU coolers we have tested in the past can claim and is a testament to the Ninja design since that it shows a slow fan is more than adequate to cool it.

Rather that rely on MTBF numbers, an easier and better way to get a “feel” for what the manufacturer thinks is the real length of time a product should last is too simply look at the length of warranty provided. The length of warranty has been calculated to be long enough so that customers feel secure in purchasing it BUT still short enough that it will be “out of warranty” when most fail. Taken for what its worth, the Copper Ninja comes with a 2 year warranty.

Overall the Kaze fan is a classic example of Scythe’s high quality products. This fan is very quiet and while this near-silence is done at the cost of RPMs, it is designed as a slow moving fan and its blade design has been optimized to move as much air as possible at such low RPMs. This makes the Jyuni the perfect fan for this cooler since the Copper Ninja has been designed so that it does not require much air movement to be an efficient cooling solution. By having relatively far apart fins combined with a huge surface area any fan movement at all is enough to cool this unit. In fact this cooler is so thermally efficient that you technically don’t even need a fan (as long as you use a very cool running chip and don’t stress it much as we will see later in this review).


The only real faults that one can find with this fan are the fact that it is not sleeved and its wires are fairly short. With the price that this CPU cooling solution commands would it have been too much to ask for a long sleeved fan cable? As it stands it does look out of place on such a beautiful work of art and does cheapen it in an almost intangible way. The fact that the wires are also fairly short did not improve the situation and just help reinforce the impression that a fan (even a high quality one like this one) was more of an afterthought to the unit.