Paraleyes

When I 1st built my system, I cut in an 80mm opening for a fan in the top of my case to blow directly down into my case. Later on, I bought an 80mm to 120mm adapter and installed the 120mm fan in the same position mostly because I was curious as to the stagnant air behind the motherboard having no way to circulate. This new 120mm fan pushed air downward into my case as well as behind the motherboard. This mod reduced my motherboard temps by 3C! I swapped it out again with the 80mm fan just to be sure of the difference. And for you skeptics out there, the 80mm fan has more than 10CFM airflow.

Unfortunately, I lost the 3C when I began another experimental modification creating a custom bent air duct around this fan directing ambient airflow onto my HSF allowing for a much more valuable result in CPU temperature reduction. The trade off was worth it in my book. I am still considering another minor mod to yet again prove the theory of dissipating heat from the back side of my motherboard. I may or not do this, but I will post results on the thread if I do.

Don't be discouraged by one review! The Hardware Canuck's testing methodology defeats the purpose of the whole idea of the Thermalright IFX-10! Here is a quote from their review: "...all comparison testing was done on an open bench..." Why didn't they perform the test emulating realistic circumstances?! How much heat is going to stay beneath the motherboard while it is sitting out in the open on a bench compared to in a case like the rest of the world would use this product? I don't know, but make your own experiments and get your own findings. Prove this theory! Somebody buy one of these and post your results here!

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UHAF 932 Prototype Concept Rig Build Log
Ultimate Aggressive Cooling Mod - How I Lowered my MB temps by 25C!
How to Modify, Cut Down & Upgrade Your Stock Heat Pipe System
Old Heat Pipes Moddded on a New P5N7A-VM Old Heat Pipes Modded on a New P5Q3

tonschk

Somehow I must add a 120mm fan at the back of the mobo tray

Paraleyes

So Tonschk,

Please tell me you logged some temperatures before you did this mod so that you can post the differences. If not, I'm curious if you flip the fan around might it do even better. I suppose it depends on how much air is being forced in or out of your case by other fans, but it may be worth trying.

I have been planning to mod in a few low profile fans in the back of my MB like that since I ran into this thread; one over each chip. I'll post before and after logs when I get around to it. The issue I'm having with this is the fact that I want my case to look like I bought it this way by the time it's all said and done. I guess I should spend some time thinking on this.

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UHAF 932 Prototype Concept Rig Build Log
Ultimate Aggressive Cooling Mod - How I Lowered my MB temps by 25C!
How to Modify, Cut Down & Upgrade Your Stock Heat Pipe System
Old Heat Pipes Moddded on a New P5N7A-VM Old Heat Pipes Modded on a New P5Q3

tonschk

I dont have done this mod , I took the photos of this mod from another forum , the fan added at the back of that allumunium motherboard tray is a 140mm Sharkoon Fan, in the link below you can check the effect of a heatsink added to the back of the PCB of a nVidia 295 graphic card , 20 degrees Celsius decreased the temperature of the video card ( at LOAD )

A warning , the heatsink added at the back of a PCB can be extreme dangerous , a properly thermal pad enought thick is needed to avoid direct contact, if the PCB touch somehow the metallic heatsink the motherboard can become dead

http://www.overclock.net/nvidia/4503...ce-tested.html

SLeeZeY

I just cut a hole in my backplate and put a small fan mounted to blow air round the back of the mobo (directly on to the back of the CPU seat), cuts about 4*C of the overall temps, so it isn't to be ignored.

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Slink

Such a configuration would do well to employ ductwork for control over airflow. Without ducts, air can just go "where it wants", and that's the path of least resistance. This means that optimal cooling would not occur (I.E. Optimal cooling might be airflow across the back of the mobo from the bottom of the case, up to an exhaust behind the board).

Silicone caulk would make for an excellent dielectric sealant to close off the sides of the board into which you do not want air to be draw, I.E. the sides of the board. I'd leave the bottom open and caulk between the case/mobo tray, and vertical edges and the top edge of the mobo to allow the only intake for air to get behind the mobo to be the bottom edge of the mobo. Caulk might be kinda permanent though... ;-P

I'm thinking about doing a duct casemod on my rig...

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SLeeZeY

I'll take some pics when I have all my parts ready for my rebuild, but tbh its just a huge hole in the backplate, nothing special lol

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Paraleyes

This is actually an interesting idea. "PURE SILICONE" only though. It would peel right off as long as you didn't smear it flat on the edges. If you used a painters caulk or any type of mixed product, it would be a mess and most likely melt if it got hot! Not good.

Better yet, use some weatherstripping to box in around three sides of the CPU. I'll illustrate a diagram. This would make a perfect gasket against the back of the MB tray ensuring a constant flow of air directly behind the CPU by whatever fan used consequently removing any thermals conducted from the back of the chip through the circuit board to be pulled out of the case.

Thanks for posting your results!

I'll be doing this mod soon after I find the right fan and grill for the project.

EDIT: That was easy, I found the fan I hoped for(80mm X 80mm X 15mm). It will give me exactly a 1/4" gap between the back of the MB and the fan when it's all said and done. I'm ordering the parts tonight and as I said, I'll be posting my results here when I'm done including before and after CPU and MB load temps. Don't worry, I will be sure to match ambient room temps while testing.

__________________

UHAF 932 Prototype Concept Rig Build Log
Ultimate Aggressive Cooling Mod - How I Lowered my MB temps by 25C!
How to Modify, Cut Down & Upgrade Your Stock Heat Pipe System
Old Heat Pipes Moddded on a New P5N7A-VM Old Heat Pipes Modded on a New P5Q3

Grandlo

mosfets are designed to dissipate heat into the board (dissipate to the bottom) so it does some good there I'd imagine. for the back of the socket, I think it might shave a few c off your socket temps but don't know about core.

zipdogso

What some of you appear to have missed is that ASUS boards with STACK COOL 2 are designed to dissipate heat off the back of the board - it is a specific design of the motherboard a fan in this area could help overall temperatures on the board. Unfortunately not all higher end boards have it.