[francis]

Hi, I decided to write to this forum about a problem I have with a particular version of the Slip Stream model fans, I am speaking of the Scythe Slip Stream SY1225SL12SH, the one with a maximum speed of 1900 rpm.

I also have two other versions of this fan, the SY1225SL12L (800rpm version) and SY1225SL12M (1200rpm version), having no problems with these two fans.

The problem of this fan is due to the fact that it increases its speed too rapidly from the speed of 800 rpm to the speed of 1600 rpm.

In the link below I show the behaviour of this fan depending on the voltage.
The initial speed of 820 rpm in the first graph is obtained at the voltage of 8.90 V, but then if we increase the voltage by only 100 mV to the voltage of 9 V, this fan goes up to a speed of more than 1600 rpm in a blink of an eye.

http://i264.photobucket.com/albums/i...ream1900-2.jpg

For this reasons it becomes extremely difficult to set this fan within the speed range starting from 800/900 rpm to 1500/1600 rpm.
It a very disappointing and time consuming task, to put it plain and simple I went crazy trying to set this fan at certain speeds.

I used three kinds of Rheobus, Zalman MFC1, Scythe Kaze Master, Zalman MFC2, always getting the same results.
I doublechecked the voltage first with a Lafayette DMB-2 and then with a Lafayette DMB-4: same results on both.

In the Everest graph and when using the Zalman MFC1 I got the speed from a mb Asus P5K Dlx.