Problems with Slip Stream 1900rpm.

[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.

[Shinigami]

Hi francis,


Thank you very much for your message. I just tested the same thing with 2 of my fans (2 different batches).

Spin up was at 5.5V but I was running them at 5v=400rpm, 9v=900rpm. Once you lowered the rpm and go up again it feels that the increase of voltage around 9v is growing only slow, but the rpm are picking up constantly and don't jump uncontrolled. The range between 9 and 10v is bigger, it is 900-1500rpm, which I could increase and decrease steady, nit a big problem on my side. I was using the Kaze Master 5,25" black for the test, to simulate it.

You seem to have tested it pretty often with different control devices. So my guess is that you have the lucky one, which you should replace. If you are from Germany, we can do direct RMA Procedure. Otherwise please contact the shop and send them this link, as it is involving us as the manufacturer as well and It was my advise after all.

[francis]

Thanks for your help (and sorry for being late in replying).

I have received another unit of this fan, but sorry to say it behaves the same way of the older.

As far as I can notice this fan may reveal itself very difficolt to control, but anyway I think I can live with it.

[cromelex]

I've decided to buy a bunch of scythe slipstream fans for my pc case. Unfortunately I'm unable to find the 1200rpm versions available here in Portugal right now.

I'd like to have my fans running at ~1000 / ~1350 rpm if possible.

I saw a review on SilentPCReview on these fans and they claimed that, at 5v, the 1600rpm version would do roughly 900rpm. I wanted to know if that number is correct. Seems suitable for me.

I have no fan controllers, and my motherboard lacks the 3pin connectors for all my fans, so I can only get 5v or 12v without hard work. Maybe 7v but I heard that is not so healthy for PSU's.

[hiroshige]

Hello cromelex,

there is no guarantee that the fans will start working at 5V - maybe you need a short boost with a voltage which is higher than 5V, i have to check this. We are moving to a new office, so testing could last a bit longer until we are completely moved in.

Cheers,
Stefan