Heat dissipation and case mod idea.

I had a question regarding a new case mod idea. I wanted to attempth something similar to this. For those who can't follow the link...its basically a semi passive cooled system. Two large heatsinks reside in the center of the case with the gpu and cpu attached on each side.

I would be using a CPU that is 65TDP and a Cpu that is 75TDP (Nvidia Quadro).

My idea would to throw this in an Osmi case...with two large heatsinks in the center interlocked. CPU attatched on one side like I said before, and the GPU the other. In the Osmi case..the GPU will have to switch to a vertical position. Are there PCI riser cards that can do this...or can the existing ones bend?

I guess my main question is heat. If there is one 140mm fan blowing down over the heatsinks..will that be enough? HDplex's GPU heat sink has a max TDP of 90w...and the CPU def falls within the specs.

Thoughts/Comments

I think I've seen someone do this before, not sure where.

There are a lot of flexible PCIe risers from 3M, HDPLEX, LiHeat and ModDIY, all of which could do the job in theory. I guess you want to mount a fan below this whole apparatus, so the long version of the 3M riser is probably best. You can just fold it to the side, so no vents will be covered up.

I don't know which tower heatsink would be small enough for this to work in the OSMI. Take a look at its dimensions and try to find out whether this could actually work out spatially. Other than that, a single 140mm fan is quite certainly enough to cool the components you're planning to use.

How are you going to do power delivery? External brick?

Pico PSU since it will be around 160TDP. I was thinking of grabbing an aluminum heatsink off of ebay like this one...and just interlacing the two.

Those things are NOT effective in terms of heat dissipation! They claim it can dissipate 90W, but you have to distribute the heat over the back of the heatsink with heatpipes or a vapor chamber yourself, and even then I can hardly see this working. I mean you can try, nothing's stopping you, but I wouldn't expect that to work.

I thought you were going with some small tower coolers for 80mm fans or something like that.

There would be copper heat pipes though...similar to what the guy did here. I would have something setup like that with one 140mm fan at top...and perhaps one on the bottom as exhaust. Would this still not work?

iFreilicht said:

They claim it can dissipate 90W

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Actually what they claim is, specifically, that "90W of high power CREE LEDs will run at around 35C above ambient." That's not the same as 90W of total heat that needs dissipating, since of course a 90W LED is going to convert some of the energy it uses into light. What you want to look at is the thermal resistance, which in this case is 0.53C/W. Dividing the delta T by the thermal resistance (35/0.53) gives you the actual heat dissipation capacity: 66W at a delta T of 35C.

Keep in mind that's the passive airflow rating, and any active airflow across the heatsink will improve the thermal performance substantially. But you're right about needing a good heat conduction (via heatpipes or vapor chambers) for optimal performance.

Necere, is there a calculator of some sorts to estimate the aluminum block size needed based on an devices TDP? Or is your formula of Thermal Resistance divided by temperature what i should use?

fminus said:

Necere, is there a calculator of some sorts to estimate the aluminum block size needed based on an devices TDP? Or is your formula of Thermal Resistance divided by temperature what i should use?

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Google "heat sink calculator." You'll probably need to do some studying to get a good understanding of the variables, but it's worth it in the long run.

While you're looking at G4 cube builds for inspiration, the Silent Cube build may be useful to you. It uses the same copper heat pipe mounts with a LED heatsink for the GPU that meshes with the original one (see this pic). It uses a GTX 750 Ti, though, so it would produce less heat than your GPU.

CC Ricers said:

While you're looking at G4 cube builds for inspiration, the Silent Cube build may be useful to you. It uses the same copper heat pipe mounts with a LED heatsink for the GPU that meshes with the original one (see this pic). It uses a GTX 750 Ti, though, so it would produce less heat than your GPU.

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That was the original source of the idea. I ended up imagining it in the Osmi case just because accessing the ports would be easier.

I thought of an additional setup like this...but as I said before, I am not too knowledgable of the thermal dynamics of this.



I used the Silverstone HE01 as an example. The CPU cooler has a max TDP of 300w...Which might allow me to swap the video card with another GPU with a higher TDP and use heatsinks on the vrm. How stupid/feasible is this idea?

A guy (or girl?) over at another forum was thinking of a similar internal layout, but with the cooling towers nested in a stack with fans only at the top and bottom. He (or she) also chose the HE01 because of its slimmer towers fitting within its fan-spaces between towers.
That config uses only two heatsink fans - at the top and bottom, plus a very large "case fan" at the top cooling also VRM, chipset, RAM, GPU-RAM etc.

This makes much more sense and will probably work if you can fit everything into the case. The thread Findecanor is talking about is probably this one.