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placing a heatsink on the back of the mobo where cpu is.

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vincent_1985

Member
Joined
Dec 2, 2003
placinga heatsink on the back of the mobo where cpu is.

would htis be effective at all?
then i can take heat off both sides of my chip!
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
I have been running something like that setup for nearly 3 weeks now.
Not a heatsink, but rather, a fan.

041203-mini-Twinfan.jpg.jpg

Yes, it helps.
In my case, 2-3 degC.
Another member who has also done it is claiming even better results.[
 
Last edited:

eobard

Give me a break Senior
Joined
Jul 12, 2001
Backside cooling for GPU's is something that's been done for a while, wether it's sinks or fans (or both), it's only a matter of time before it becomes a common thing for motherboards too. Just remember that it'll be less effective on a motherboard because the CPU is raised so much off the board. I wish I could find the link but there is an old article from the front page where the space within the center of the CPU socket for a Socket A motherboard was drilled out of the motherboard so a fan could blow directly onto the underside of the CPU. That was a really cool looking mod. DO NOT DO THIS UNLESS YOU KNOW 100% THAT YOUR MOTHERBOARD DOES NOT RUN ANY ACTIVE CIRCUIT LINES WITHIN THE CENTER OF YOUR CPU SOCKET.
 

9mmCensor

Disabled
Joined
Oct 23, 2003
Location
Banned Camp
It may lower the temps due to where the thermoresistor is but it wont lower the temperature of the actual cpu, so its useless.
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
9mmCensor said:
It may lower the temps due to where the thermoresistor is but it wont lower the temperature of the actual cpu, so its useless.
I disagree.
I seriously doubt that the thermistor is being affected at all.
At worst fresh air is being forced up the back of the board and helping to evacuate hot air from the dead air space above the HSF and below the PSU.
That's my theory at least and I'm stickin to it...:p
 

johan851

Insatiably Malcontent, Senior Member
Joined
Jul 24, 2002
Location
Seattle, WA
Might cooling the backside of your mosfets help?

Also, it might lower more than just the reported temps. Some of the heat has to be conducted through the little solder points on the back...so while it would MOSTLY only cool the sensor, it might cool a little bit of the processor too.
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
Okay, I admit it.
I have no clue why this seems to drop my temps.
But it does.
How do you figure the air is getting through the board to only cool the sensor?
 

archilochus

THE Senior FANMAN
Joined
Sep 26, 2003
Location
Houston,TX-USA
I think there is a dead zone behind the mobo.With air introduced
to the back of the mobo you are eliminating the dead zone,by moving the heat out. THE FANMAN:cool:
 

clocker2

Member
Joined
Dec 5, 2003
Location
Mile High
archilochus said:
I think there is a dead zone behind the mobo.With air introduced
to the back of the mobo you are eliminating the dead zone,by moving the heat out. THE FANMAN:cool:
I suspect that this is exactly correct.
Now the question is...is it better to blow fresh air IN or to flip the fan and suck it OUT?
I have always tested while blowing in.
I guess I'll bite the bullet, strip out the motherboard and reverse the fan and see what happens.
I'll let you know.
 
OP
V

vincent_1985

Member
Joined
Dec 2, 2003
ya if hot air does build up back then shooting it out would be optimal because you should already have a good flo of air intake right? =)
 

PsycoPhreak

Member
Joined
Dec 13, 2001
What you have to realize is that as the cpu heats up, this heat not only gets pulled off by the heatsink, but the pins on the cpu are also distributing this heat to the socket, and in turn, to the motherboard. In effect, heating up the traces and any small components that may reside under there.

Being that not alot of air, if any at all gets under the socket, the area undeneath is definetly holding some heat, by cooling off the back of the motherboard, your allowing that heat to be removed, not very much, but enough to notice a difference.

I have seen it work, and for those that think its just the sensor under the cpu, how can you explain a temp drop with a cpu that has NO sensor on the board underneath?

It does work, although, your results may vary. :D
 

SysCrusher

Member
Joined
Dec 1, 2002
9mmCensor said:
It may lower the temps due to where the thermoresistor is but it wont lower the temperature of the actual cpu, so its useless.

Wrong. It does work. Different results with just about all setups though. I have no sensor in my socket so temps are reported from the core sensor. Cutting a hole there and mounting a 40mm fan dropped my temps 5C. Didn't help the overclock though.
 

SysCrusher

Member
Joined
Dec 1, 2002
The back plate? The motherboard mounting plate just under the socket. It'll work and help temps but it won't help the serious overclock much. It helped my load temps. I just hit 48C on load. Before it would hit 53 - 55C on load.

Water cooling my pc it didn't help much at all. Maybe 2C on a warm day.
 

eobard

Give me a break Senior
Joined
Jul 12, 2001
I took the liberty of fixing the typo in the title, "placinga" was driving me crazy!
 

CrystalMethod

Senior Band Wagon Jumper
Joined
Jun 9, 2001
Location
Montreal, Quebec, Canada
I don't think it will help you overclock that much, but I do think it will help with system stability, by lowering overall system temps. Which COULD, not WILL lower CPU temps. Some may see a drop in CPU temp, while others wil not. 9mm does have a point. Although I wouldn't say it definately won't make a difference, I wouldn't expect too much out of it unless your pushing the bleeding edge, and are fighting for that 1-2 Mhz gain. It's still a cool mod in my books, wether it works or not. Does it work? You got a saw, an extra fan, and some free time? Those of you brave enough to try, post your results. If I get enought free time to put one in , I'll post some results as well.
 

MrBoss

Registered
Joined
Dec 6, 2003
Location
Melbourne
now i'm fighting the urge to strip my system down and start modding.

Same here...I come home from work....sit in front of the comp just wanting to drink my coffee,read something interesting and relax ....next thing I know I'm all puff pant,with drill in my hand,cuting,drilling tubing.....rushing to the store to buy something that doesn't actualy exsist or have name and when I try to explain what I want and for what I need it , guy in the store looks at me like I'm from Mars or something....

Gotta start visiting some stupid forums ,maybe I can get some rest or even save some money :)

EDIT:nice mod,will try it tomorow.... LOL
 

mikeyw

Member
Joined
Dec 20, 2010
Sorry for the massive bump but it's always better than to make a new thread about the same thing, right?

Just wanted to ask if this is still relevant in 2011. I'm considering buying an 80mm fan to exhaust air from the tiny gap between the motherboard and the tray, if it can indeed lower temps by a few degrees it's easily worth the hassle and £5!

Mike