Connecting 6800 Fan to MB header

[Shima]

Hi all,

I'm thinking in connecting my stock cooler (6800 GT) in the motherboard fan header (just the + and - wires), and control it's speed based on the temperature with speedfan.

Has anybody done it?
My question is: Can it damage the fan or the MB?

Thanks for the help.

[ViN86]

shouldnt damage either as long as the fan runs on the same specs as the 3 pin fan slot on the mobo, which i believe it does. this sounds like a good idea, i might try it. i wish my fan would go to 100% when i go into games.

my temps are good, but the cooler the better in my book.

[acrh2]

I imagine that the answer this man is looking for is exactly about 1)whether the specs of the fan of the video card are the same as those for the motherboard connector (12V?), 2) whether there will be a core/memory slowdown because of bios not being able to determine the fan speed.
As expensive and sensitive parts are involved (motherboard, 6800gt), I would only take the advice from these boards with a LARGE grain of salt. The best way to get the answer you need is to send an email to the video card manufacturer's tech support.

[ViN86]

As expensive and sensitive parts are involved (motherboard, 6800gt), I would only take the advice from these boards with a LARGE grain of salt.
ummm, theres some pretty ingenious guys on these boards. so, hang around long enough and you can tell who to listen to. i didnt know, so i didnt give an exact answer.

The best way to get the answer you need is to send an email to the video card manufacturer's tech support.
kind of makes these boards obsolete doesnt it..........

anyways, ppl have done it with their 7800GTX's and AS/zalman hsf's. wish i could give a definite answer, but someone here knows.

[acrh2]

Originally posted by ViN86
Unless the video card in question is known to be built on reference design, the specifications of the fan can be anything. Most common fan volage for modern cooling devices is 12V, which would be compatible with motherboard headers, but it is not guaranteed. One way to find out is to try to plug it in and hope the fan doesn't burn out. The other way is to measure the voltage supplied by the video card with a multimeter. The third way (if feasible), one can try and get a make and a model number of the fan in question, and try to look up the specifications of the fan on the web. Most, if not all, fans have specifications readily available on the web.
As for the possible core/ram slowdown, the best way is to test it. Of course, all these questions can be addressed in a simple email as I described above.
I don't believe that there is any danger to the motherboard from plugging in the video card fan.

The advice of listening to those whom you can trust after "hanging around" long enough is silly. You, sir, are silly.

[J-Mag]

The third way (if feasible), one can try and get a make and a model number of the fan in question, and try to look up the specifications of the fan on the web. Most, if not all, fans have specifications readily available on the web.

Delta doesn't post specs for OEM fans.

[Shima]

I found the specs of the ultra stock fan:
Delta - BFB0712H
CHARACTERISTICS:
Description: DC 12V, 0.36A, BRUSHLES, LEADS 12""
EUP: N/A
Info: 11.3 CFM
SubCategory: 0
Type: BLOWER

I think my reference GT card uses a similar delta fan.
0.36A does not seen much for the MB header.... I'll try it.
Worst case scenario, the graphic card will complain about no fan, but I doubt, since there is no speed control in my card.

Does anybody know if slowing down the fan can damage it?

[rohit]

Does anybody know if slowing down the fan can damage it?
No,
Unless you slow it to 10rpm @ 100*C.

[HOT1]

Does anybody know if slowing down the fan can damage it?
I have been running my V/C fan at 7v on a fanbus in 2D and turn it up to 12v for 3D games and no problems for the last 6 months. :D

[Shima]

I did it.
Not all my fans are controled by speedfan! :D

I even underclocked my 6800 GT to decrease even more the graphic card fan. Now I can hardly listen my computer in idle.

The fan configurations is 5% at Idle with a stable temperature of 51ºC or less, and it adds up 5% (if the temperature raises) until 100% if above 70ºC.

Conclusion: It's much quieter than before in Idle and cooler in 3D aplications, because now I can use 100% of the fan in critical situations.

[rohit]

^
| Hey congrats!!

[ViN86]

You, sir, are silly.
damn, im so offended......


:rofl