Cooling with copper, passive, active

#1

Hello @Raxda!

Will these coolers suffice?

http://www.enzotech.com/cnb_r1.htm
Dimension 44.7(L) x 44.7(W) x 30(H) mm
Weight 120g
Material Forged C110 Pure Copper
Base Flatness 0.0003
cnb_r1_photo4

http://www.enzotech.com/cnb_s1.htm
Dimension 36 x 36 x27.6(H) mm
Weight 80g
Material Forged copper 1100
Base Flatness Polished mirror surface, flatness for machined surfaces are typically in the range of 0.0003" to 0.0004"per inch

cnb-s1_photo1

And if yes, only with an active fan or even without, if they have sufficient air openings to the top of the cooler (hole in the case)?

Thank you for your answer!
Rev

PS: I already bought them, measuring the holes based on the pictures on the first design - will they fit to the new design as well?

#2
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#3

The current design might change as it is a bit off center but when @willy mentioned an adhesive would do I thought why not.

I always find if you have a tiny bit of airflow it makes huge difference and looks like there is ample space so I went oversized with a 40mm and 40mm 12v fan and just the adhesive thermal tape as have a roll on my desk. No2 16mm self tappers.

heatsink
heatsink.jpg2304×1728 222 KB

They may change it but dunno so maybe hold on or just go stick on as likely just as good.

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#4

@tkaiser
32°C cooled, 42°C uncooled, if I read your numbers correctly? And the percentage numbers in the right end of the table is the trottling?
How is that possible?

@stuartiannaylor
Thanks! If the holes fit, I will use thermal paste, no tape. Temp-flow will be higher (faster) on copper than on a small aluminium cooler, but I will consider adding a fan (also 40mm) to the 5V header.

Thank you both!

But both answers do not really answer my question, sorry. OK, let me ask it differently: how high is the guessed probability, that these copper cooling solutions will fit and work for desktop/multimedia use under linux (Audacious, MPV (HEVC, H264), Kodi, Firefox, FreeTube, streamlink with twitch-gui, LibreOffice, mumble, element, etc.)? Please give me your educated guesses. Thanks!

Rev

#5

% in the referenced post is CPU utilization, throttling is on the left side: the clockspeeds reported

CPU utilization is not a defined metric since you can have 100% CPU utilization with some lightweight stuff while some serious task like 7-zip compressing/decompressing needs a lot more juice and generates a lot more heat while showing less CPU utilization.

From the set of CPU bound tasks I’m familiar with usually cpuminer generates the most heat but on RK3588 it’s 7-zip’s multi-threaded benchmark most probably since the memory interface is that great (64-bit, amazingly fast).

#6

Dunno as said as maybe the current mount may change but you could prob save yourself a couple of dollar and have a heatsink that is equal.

Its not the copper that takes the heat away really as that is the air that surrounds the heatsink, so really its about surface area and both alu & cu are far more conductive than the air.
Where it matters is the CPU lid to distribute the heat as quick as possible and a copper shim here with a cheap alu is likely as just as effective and much cheaper to go bigger (more surface area in air) if passive.

Posting also as on a copper hunt myself but for a 20x20mm 2 or 3mm copper shim and must be one somewhere but somehow not seeing. If Anyone spots one will you post?

#7

Thank you two for your clarifications and answers!

@stuartiannaylor
10x10 and 20x20 copper pads (shim) and small heat sinks you can find on aliexpress, I think.

Like this one:

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#8

Yeah I am also in the hunt for more copper but looks like 1.2mm might be as thick as 20x20mm you can get, but was looking for thicker.

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#9

By the way, both full copper coolers do NOT FIT, so please avoid buying them in advance.

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#10

I ended up getting one of these and its far better than the store ones as the adjustable lugs allow you to position much better with the heatsink very close to the ports with a considerable gap to the gpio so the cpu is actually more central.
No horrid thermal pads just a little grease…

Still getting 1.25mm fan headers with an order seems impossible and managed to get some fly leads and snip a diy job.

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