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So I have a Eee PC 701 4G (only the motherboard!) and I don't have any cooling on it. It's a 900Mhz CPU so I think it needs cooling!!

How can I power my 12cm fan from it? I tried it powering through two USB port, but the fan is too slow.. (maybe because it gives 5V and the fan would need 12V?)

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migrated from Jun 7 '12 at 20:13

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This would be better off on Super User –  SmallClanger Jun 7 '12 at 20:04
It is a 900MHz capable CPU, but it is underclocked to about 600MHz. (580Mhz for the Eee701 surf (2GB)). I have the latter and it uses no active cooling at all. Just two thermal pads to the bottom plate of the keyboard (and in my case the CPU pad failed to make contact with it). So cooling should not be a problem. Any fan will do. Even a heatsink without a fan will suffice. –  Hennes Jun 8 '12 at 14:58

2 Answers 2

up vote 2 down vote accepted

I know your question asks re a 12cm fan, but that big may not be necessary. See how hot it gets.

If you did want 12cm, you could power it from the mains/acdc.

For example any USB-SATA/USB-IDE adaptor comes with a plug with something like a 4 pin molex or similar,like a sata power connector. So, either way, with 12V, and the fan can connect to that whole plug, it may need an adaptor but they're easy to get.
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Laptops tend to have small cpu fans. alternatively, there is this option(I see it titled mini vacuum air extracting usb case cooler cooling fan). Looks like it goes adjacent to the vent. But since you have just a motherboard you could blow it elsewhere. Just onto the hot part.

If there's a metal plate over the CPU that takes heat, then you would blow onto that.

I'm not sure how you'd do that with a blower on the side - maybe build a tube to redirect the air (let me know what you'd use to do that if you do). Assuming the CPU is on the bottom of the motherboard, you could raise the laptop a bit and blow the air under it from the side that may do it. Or, use a fan below it as you seem to plan to do.

enter image description here

You can also get a more typical laptop cooler, a laptop cooling pad, some have a big fan like 14cm.. pluscom do a 14cm one and they do a 12cm one.. The description says Aluminum USB Notebook / Laptop Cooler 12cm Fan with speed control Switch & 2 USB ports So, it is able to get its power from 2 USB ports. You can get ones with 3 small fans too. All USB powered no ACDC adaptor.
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Thats a really odd adaptor - what would it be practically used for, other than powering fans? –  Journeyman Geek Jun 8 '12 at 9:51
it blows air in or sucks air out(probably sucks for that device). it cools a laptop. The fan is in it. Just the little fan inside it. That area it is adjacent to is the vent of the laptop. Infact I dreamt such a thing up and then found it existed..thouh i'd want one that took a 12cm fan like the questioner, though i'd want 12cm 'cos they can be a bit quieter while pushing the same amount of air. I found that when I blew reasonably cool air into the vent of my laptop from my mouth, it cooled it down. So a device of that structure is only natural and could be built as a DIY task. –  barlop Jun 8 '12 at 15:29
I don't know for sure what that round thing in the middle of the USB cable is, it's not relevant to the cooling and it's probably just a retractable usb cable type thing –  barlop Jun 8 '12 at 15:33
@JourneymanGeek I suppose these things are useful if your laptop doesn't cool itself sufficiently. Or, if its own fan goes up when the cpu temp reaches a certain level, but it goes on too loudly. It can give more control over things in some ways, when the cooling is external. –  barlop Jun 8 '12 at 15:59
No, the other one , the one that looks like a laptop charger ending with a mplex connector –  Journeyman Geek Jun 8 '12 at 17:10

Depending on what fan you have currently, you may be able to manage the fan speed with a fan control application, if your system recognizes your fan, Speedfan is an example here

if powering it from the computer does not provide enough power, you may have to seek an alternative power source. In the past i have got a 240V to 12V adapter and spliced the cables to power the fans in my entertainment unit. For portability this is not great, so you may have to look at other 5V fans available that may have a faster RPM, an example would be this.

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