Plugging a case-fan(3-pin) into a graphicscard(2-pin)

[andepro]

I want to put a 90 mm casefan on my GPU-cooler but still attached/controlled/powered by the graphicscard itself. The 7800GT has a fancontroller that can change speed between 2D and 3D, which I'd love to keep using.

The question is if this is possible:
1) Can the graphics-card deliver sufficient watt?
2) Is there an adapter for this 2-3 pin-setup (like a 4-3-pin-adapter)?

 

[Zepper]

What are the voltage and current (or power) ratings of the OEM fan on the card? Your 92mm fan would have to have similar ratings to work properly with the card's controller as fan speed is not involved in the controller's function. The connector may well be a different format too so you may have to cut the connector from the OEM fan and splice it to the red/black wires of the new fan. IOW, yes it will work as long as voltage/current specs are in the ballpark of the OEM fan.

Or you might consider using a Zalman fan/bracket kit...

.bh.

 

[andepro]

What are the voltage and current (or power) ratings of the OEM fan on the card?

Thats a good question. The accelero X1 cooler was able to use this 7800GT-card with the ability to control the fan-speed, so it should be similar, but I cant find any information on the cooler or through googling.

Do you have any suggestions in finding the answer to this?

 

[Operandi]

The stock fan is almost certainly 12v and as long as you don't use a high power (high speed) 92mm (90 doesn't exist) you'll be fine be fine as far as power draw is concerned.

As Zepper mentioned you'll want to cut the connectors off of both fans and solder the stock HS/Fs connector onto the new fan -- this has been done many times by people wiring their Zalman VF-700 or 900 into their graphics cards' fan header.

I would also pick up some heat shrink tubbing, electrical tape is not very good on such small wires.

I assume this must be for Thermalright's GPU heatsink or something similar?

 

[aigomorla]

Originally posted by: Operandi
The stock fan is almost certainly 12v and as long as you don't use a high power (high speed) 92mm (90 doesn't exist) you'll be fine be fine as far as power draw is concerned.

As Zepper mentioned you'll want to cut the connectors off of both fans and solder the stock HS/Fs connector onto the new fan -- this has been done many times by people wiring their Zalman VF-700 or 900 into their graphics cards' fan header.

I would also pick up some heat shrink tubbing, electrical tape is not very good on such small wires.

I assume this must be for Thermalright's GPU heatsink or something similar?

isnt the third wire always a RPM sensor or some sort? So as long as the fan diameter is kept small and the Amperage draw is small shouldnt it work?

 

[Zepper]

You will often find the fan mfr's label on the stationary side of the fan hub. The heatsink or card mfr often puts their own label on the moving side of the fan hub (not a good idea, IMO, due to potential for adding imbalances). Mfr's label should have voltage and current or Power specs and perhaps more info.

..bh.

 

[Operandi]

Originally posted by: aigomorla

Originally posted by: Operandi
The stock fan is almost certainly 12v and as long as you don't use a high power (high speed) 92mm (90 doesn't exist) you'll be fine be fine as far as power draw is concerned.

As Zepper mentioned you'll want to cut the connectors off of both fans and solder the stock HS/Fs connector onto the new fan -- this has been done many times by people wiring their Zalman VF-700 or 900 into their graphics cards' fan header.

I would also pick up some heat shrink tubbing, electrical tape is not very good on such small wires.

I assume this must be for Thermalright's GPU heatsink or something similar?

isnt the third wire always a RPM sensor or some sort? So as long as the fan diameter is kept small and the Amperage draw is small shouldnt it work?

Usually but the OP specified 2-pin so in this case I would assume it isn't present.

 

[Painman]

The problem I'm seeing is potentially not getting enough voltage out of the fan controller during the card's idle state to make the fan turn. Of course that will right itself as soon as the GPU starts to roast, but the fan would just shut down again once the controller's output dropped below the critical threshhold. That kind of roller coaster ride might not be good for the long term health of the GPU.

Fan choice will be important, silentpcreview may be helpful here to find a fan with low startup requirements.

 

[andepro]

I assume this must be for Thermalright's GPU heatsink or something similar?

Yes - I updated my signature now...

Or you might consider using a Zalman fan/bracket kit...

Like this?:
I am happy about the performancegain, but i seek a solution thats almost noiseless in normal pc-use (not gaming)

I found a place to buy an adapter so I wont have to solder. But I'm a little confused since your actually saying Ill HAVE to cut off the wires on both fans to migrate the functionality to the new setup.

Ill search for a good fan, with low startup requirements - thx

 

[Zepper]

Yes, that is the Zalman bracket, but it normally comes with a 92mm Zalman badged fan like this with a 12V @ 3.36 Watts (0.25 to 0.3 Amp).

.bh.

 

[andepro]

I dont understand the point with the bracket-thingie, unless theres an adapter in that setup (which i cant read out of your link).
My problem is not mounting the fan on the heatsink, but using the output and control of the graphicscard-fancontroller with a CPU/case-fan. If I get you right, I have to solder/theres no specific adaptercable for 2-female-->3-male?

 

[Zap]

I thought that the fan headers on video cards were 5 volts?

 

[Zepper]

OP,

The bracket thingie is so you can aim a fan at the vid card's heat sink w/o necessarily mounting the fan directly to it. And you don't have to hook up a fan to the header on the card (AFAICT, there is no sensing of the fan going on) - perhaps going direct to a front-panel fan controller would be better. No cutting, no splicing, you control it.

...No specific adapter... It depends on the connector - there may be one. Card fans tend to use smaller connectors than case fans Though they really wouldn't have to. Perhaps it's to keep folks from hooking 12V fans to 5V connectors. Now that many vid cards have direct 12V connections, there is no reason that a vid card fan couldn't be 12V. You might want to get one of those Craftsman meters that i posted in Hot Deals and check to see what that card fan header is putting out. If it's 5V, then back to square one. Not many of those around.

.bh.

 

[Operandi]

Maybe some of the older cards were 5v (I've never seen one) but everything now is 12v. Those small fans also actually tend to draw more power the larger medium to low speed 80-120 fans due to their high speed so you don't have to overly cautious about power draw.

Also any adapter you find may or may not be compatible with your graphics card's fan header so I would just plan on soldering anyway. That will also allow you shorten the wires up so you don't have a ton of excess wire from the fan to the card.

 

[andepro]

I must admit, that Im going for the easy way - meaning the adaptercable. I must confess though, that Im attracted to the idea of being able to control things myself - improving solderskills (I dont even have a soldering iron :]). The information Ive achieved here is great though. Thx all!

 

[Painman]

A craptastic Radio Shack soldering iron is good enough to get you started down the DIY path. Cheap, too. Fan wiring is an easy, low risk source of practice.

 

[andepro]

Hehe...some words are not easy translatable for me. Americans tend to love shortening of words like ex. DIY

Danish I am - learn the language I must [Master Yoda ©]