Changing a6 3670 llano HSF

[wannabgeek]

Hi i am just about to build a pc with a A6 3670K CPU going onto a Gigabyte A75 UD4H mobo and i want to replace the cheap llano stock fan with something slightly better,which is the AMD phenom II 1055t stock fan from my previous build. Heres my problem. The phenom fan for some strange reason only has 3-pin socket (llano has a 4-pin pwm-1 extra yellow wire) I do have a 3 to 4 wire convertor which came with a case fan but this only connects via a molex connector do you have Any ideas ps? Thanks

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[scaryjim]

The 4 pin fan header will have the keying guide offset to one side. Just slide the 3 pin fan connector from the Phenom cooler onto that end of the header. It means the fan won't adjust its speed with the temperature of the CPU, but it'll work fine.

Alternatively, if the fans on the coolers are the same size you could just swap them over - it should be a straightforward job, just unscrew both fans, swap them, then screw them back on again!

For a bit of background: the four pin fan wire is for a technology known as PWM, which allows the motherboard to change the speed of the fan automatically based on a trigger sensor - usually the CPU temperature. If you compare the two fan connectors, you'll see how the 4 wire PWM connector is basically the same as the 3 wire connector, just with an extra bit stuck on for the fourth pin. The only difference using a 3 pin fan makes is that the fan will always spin at full speed - so your computer will be slightly louder, but your CPU should stay slightly cooler. In technical terms it makes no real difference.

[wannabgeek]

Thanks v much jim.
I think i would rather the mobo control the fan as i hate the noise. Also Cant change fans as 1 is smaller. The cpu clamp locks actually look different sizes, and one looks to be slightly lower. Do you know if they definately fit? 1055t is on the Am3 and llano is on the F1 i think. Thanks

[scaryjim]

AFAIK they use the same mounting mechanisms, but I don't have an FM1 board so I can't be 100%. That said, AMD have used the same mounting mechanism since the s754 / s939 days, so I'd be surprised if they'd change it significantly...

Since you've previously been using the Phenom II stock cooler on your old build, I assume you already know what it sounds like, so you should know if you can stand that level of noise on your new build! Transferring the cooler from one build to another won't suddenly make it any louder, so if your old PC was acceptably quiet then your new PC will be too, even without the PWM control. On the other hand, if you think your existing PC is too loud, then you're probably better off getting a new cooler rather than trying to hack together something from the old one.

[DanceswithUnix]

Before mucking about with fan swapping I would try just plugging it in.

With 3 wires the motherboard does the PWM power control instead of building that electronics into the fan. Certainly early motherboards with 4 pin fan headers could do both, and the end result is exactly the same (fan speed changes with cpu temperature).

Just plug it in, turn on cool & quiet in the bios, and from my experience it will just work. If you don't get fan control, I would have a dig around the BIOS screens to see if there is anything relevant in there.

I think the idea of the 4 wire system is that the motherboard designer doesn't have worry about switching power on some of the huge fans that heatsinks use these days. If the fan motor is huge, then that becomes the fan designers problem. With the sort of fan sizes you get at stock (usually about 70mm) that isn't an issue.

[wannabgeek]

Thanks guys and sorry for late reply.

Since you've previously been using the Phenom II stock cooler on your old build, I assume you already know what it sounds like

Have not used this cooler yet as used aftermarket coolermaster

[scaryjim]

Have not used this cooler yet as used aftermarket coolermaster

Ah, fair enough. I think this may answer my question in your graphics thread as well!