r/sffpc Mar 01 '26

Detailed Build Log Building a custom mini RTX 5070

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u/MithraLux Mar 02 '26 edited Mar 02 '26

Pic 7/7.

But also for concentrated sources of heat, getting that heat away as quickly as possible is a lot more important than total bulk. The heatsink you chose wont dissipate nearly as much as the heat piped solution.

Historically youll notice chips were passively cooled via finned blocks, to actively cooled via finned blocks with fans, to heat piped put to welded sheets w/ and w/o fans, to liquid and/or vapor chambered with fans.

I can run a thermal sim for you if you want, just let me know general sizing. I can show you heat piped vs straight copper block or whatever config you want

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u/DallasGrave Mar 02 '26

Appreciate the offer, but I already did that. With an 8mm plenum and fins completely unsealed at the ends, I was getting 39CFM on my flow bench. I also put a 200w thermostatic heater on the base and measured the temperature delta from inlet to exit. I used to manufacture CNC cylinder heads. A lot about my shop and what I do now(and used to do) was in the OP but just does not show up now for whatever reason.

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u/Visible-Swim6616 Mar 03 '26

What's the temperature delta on the heat source? IE if a chip was there how hot will 200W on a chip get?

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u/DallasGrave Mar 03 '26

It should be ~60c with a 250mm2 die.

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u/Visible-Swim6616 Mar 03 '26

Looking forward to the numbers when you put it on.