[Build Log] Passively Cooled 400W/300W TDP System Under 100$

[iamdarkyoshi]

Update: Thermal paste EVERYWHERE

Spoiler

Got one heatsink panel made and I have made mounting hardware for the GPU heatpipe squid.

 

Here is the heatsink panel:

 

And here is the GPU heatsquid:

 

I have not mounted the heatsquid to the heatsink panel yet, nor have I made any temporary cooling solution for the VRMs and videoram on the 8800gts, which will be my test card. I have also not added thermal paste to the heatsquid as I will need to be taking it apart quite a bit.

 

@Stefan1024 When I go to test the 8800GTS which has a TDP of roughly half of the 390x and I want the 390x to reach a max of 80 degrees, what temp should I hope for on the 8800gts with an ambient temp of 25 degrees?

 

Hopefully I can do some testing tomorrow. Note that the heatsquid side of the GPU heatsink will also have heatinks on it, so a 2 sided heatsink with a GPU in the middle. Or rather in the corner...

 

 

[thekeemo]

How will the system once assembled look like?

[iamdarkyoshi]

1 minute ago, thekeemo said:

How will the system once assembled look like?

A sandwich of heatsinks, aluminum panel, GPU/more heatsinks, heatsinks, panel, motherboard

[Godlygamer23]

Thread moved to Build Logs.

[thekeemo]

16 minutes ago, iamdarkyoshi said:

A sandwich of heatsinks, aluminum panel, GPU/more heatsinks, heatsinks, panel, motherboard

Can you do a paint sketch?

[iamdarkyoshi]

Just now, thekeemo said:

Can you do a paint sketch?

Nah its past bedtime so PCs are off...

[Stefan1024]

1 hour ago, iamdarkyoshi said:

Update: Thermal paste EVERYWHERE

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@Stefan1024 When I go to test the 8800GTS which has a TDP of roughly half of the 390x and I want the 390x to reach a max of 80 degrees, what temp should I hope for on the 8800gts with an ambient temp of 25 degrees?

 

 

Nice!

 

Once you reached equilibrium (will take about an hour), the thermal resistance is a linear function.

 

Half the TDP -> half the temperatur difference: (80 - 25) / 2 +25 = 52.5 °C

[iamdarkyoshi]

Small update: good and bad news.

 

The thermals are pretty bad right now for a couple reasons.

 

The thermal paste I used on thr GPU has a thermal conductivity of 1.2w/m.k

 

My heatsquid covers about 50% of the panel, mostly the left bottom. The right side is pretty much cool.

 

The heatsinks ehere the heatsquid is mounted are warm, but not really hot...

 

Anyway when I started unengine heavrn, the temps shot to 70 very quivkly and just stayed there. It has been running for about 10 minutes with a room temp of 20 degrees and it is now 77 degrees. The hottest heatsink feels like it just hit 50 degrees and most of them are in the 40-25 degree range. I need to add more heatpipes snaking back and forth on the back of the panel. Good thing I have a shitload of them.

 

Yah also my VRAM cooling solution is working horribly, so they have a fan pointed at them...

 

This is seriously linus level ghetto mounting right there...

[Stefan1024]

Haha yes that's very DIY looking. I like it.

When the temps rise fast at the beginning means you have a bad heat contact between the chip and the big heat sink(s). When they rise a lot over time, they are overpowered and need a high temperature to get rid of all the thermal power.

To me it looks like your mounting preasure is to low. It requires a considerable amount of force. When the PCB starts to bend (but only bend it a little bit) it has enougth preasure. Looks like the twisted strips are not up to this task.

[Stefan1024]

Any news for this awesome project?

[nycesquire]

As a fellow passive cooling enthusiast, I must also follow.  Any updates here?

 

Take a look at the thread in my sig to get a sense of my passive cooling rig, which is still in progress.  One lesson learned from my solidworks simulations: this is not a heatsink size issue; it is a heat spreading issue. You need more heat pipes and greater contact between the heatpipes and the heatsink(s).

[iamdarkyoshi]

11 hours ago, nycesquire said:

As a fellow passive cooling enthusiast, I must also follow.  Any updates here?

 

Take a look at the thread in my sig to get a sense of my passive cooling rig, which is still in progress.  One lesson learned from my solidworks simulations: this is not a heatsink size issue; it is a heat spreading issue. You need more heat pipes and greater contact between the heatpipes and the heatsink(s).

Its a project on pause right now. I am very busy.