toldcodger
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Heatsink on the LAN Chip

Thu Aug 02, 2018 11:38 pm

Hi,

I have a RPi 3B+ and my case has a hole above the LAN / USB chip. It’s the black chip in the middle of the board just behind the USB ports.

I know everyone says the RPi doesn’t need heatsinks, but would it do any harm to put a heatsink on it.

I have a heatsink with a self adhesive thermal patch that could be made to fit.

Regards

Dave

Brandon92
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 12:04 am

Hello,

It will help to stay cooler. And I think it wouldn't harm it.
But if the adhesive is to strong, you could damage the chip. When removing the heatsink.

But, I think the main chip "wants" a heatsink more than the lan chip.

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Imperf3kt
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 5:45 am

Its up to you if you want a heatsink. It is unlikely you actually require one, especially on the LAN chip, but it won't hurt to put one there if you feel so inclined. Just make sure it cannot move around as heatsinks are generally conductive and can short out your Pi (possibly destroying it) if allowed to touch other components that it shouldn't.
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LTolledo
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 6:08 am

All my RPi3B and RPi3B+ have heatsinks on the LAN chip. Its my requirement for the system.
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 6:38 am

LTolledo wrote:
Fri Aug 03, 2018 6:08 am
All my RPi3B and RPi3B+ have heatsinks on the LAN chip. Its my requirement for the system.
Does it make any difference to the LAN or SoC performance?
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jahboater
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 7:38 am

Thermal images often show the LAN chip as the hottest component.

See this post for example:
https://raspberrypi.stackexchange.com/q ... spberry-pi

However, I doubt it really needs a heat sink though, but it does no harm.

The kintaro heat sink (the best around I think) has a pad for the LAN chip.

toldcodger
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 8:37 am

Thanks guys,

I know it gets hot but it’s more my OCD. There’s a hole in the case lid ... it needs something in it :)

Regards

Dave

LTolledo
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 9:08 am

jamesh wrote: Does it make any difference to the LAN or SoC performance?
I never measured it and have no means to measure it. Its known to get hot though (temp above 40C but below 60C)

Better safe than sorry and regret later on...
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Come to me with 'problems' and I'll help you find solutions"

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jamesh
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 9:16 am

LTolledo wrote:
Fri Aug 03, 2018 9:08 am
jamesh wrote: Does it make any difference to the LAN or SoC performance?
I never measured it and have no means to measure it. Its known to get hot though (temp above 40C but below 60C)

Better safe than sorry and regret later on...
I'm not aware of any throttling that goes on in that chip if it overheats, so the only effects this might have is to increase the total thermal mass of the device, and to provide a little extra heat disipation. ie instead of the heat going in to the PCB giving an overall heat increase (and the possibility the SoC hits a thermal limit earlier), it sheds more to the air.

It would be interesting to see figures.
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RaTTuS
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 9:48 am

jahboater wrote:
Fri Aug 03, 2018 7:38 am
Thermal images often show the LAN chip as the hottest component.

See this post for example:
https://raspberrypi.stackexchange.com/q ... spberry-pi

However, I doubt it really needs a heat sink though, but it does no harm.

The kintaro heat sink (the best around I think) has a pad for the LAN chip.
that is from a model 1 raspberry pi - the newer ones need it even less, the best heat sink is the one that combines a metal case .
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jahboater
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 10:11 am

RaTTuS wrote:
Fri Aug 03, 2018 9:48 am
that is from a model 1 raspberry pi - the newer ones need it even less
OK.
I did wonder if the Gige version on the Pi3B+ might get hotter.

jamesh
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 10:18 am

It does - the power requirements to drive the cable at gig speeds are higher, and the chip just seem to run hotter. In fact hotter than the SoC.
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toldcodger
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Re: Heatsink on the LAN Chip

Fri Aug 03, 2018 10:45 am

I have a multimeter at work that measures temperature. I’ll do some before and after checks and see if there is any difference.

I’ve made a fan that senses the cpu temp and varies the fan speed accordingly

I got the heatsink in a pack of 12 at the Maplins wake. It’s a bit long but I’ll cut it down.

Regards

Dave

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mahjongg
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Re: Heatsink on the LAN Chip

Sat Aug 11, 2018 8:27 pm

The very first PI (the PI model 1) had a design error that caused the LAN/USB-hub chip to get much hotter than normal, so that might explain why on early thermal images the LAN chip is the hottest chip on the board. normally (on later models) that had this bug fixed that isn't the case anymore, and while the latest gigabyte LAN chip uses a little more power it still does NOT need a heatsink. The only reason some resellers do provide one is so they have more to sell. A heatsink on the SoC of models 3B and 3B+ may have some use, especially to keep them from throttling the CPU clock if they heat up, but not on the LAN chip.

runboy93
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Re: Heatsink on the LAN Chip

Wed Aug 15, 2018 5:54 pm

This case will keep your 3B+ model cool, thermal tape / pads are recommended to use with case, thickness of 0.15mm somewhat thin, bad to none contact (0.25 - 0.5mm takes contact, differences comes with pressure), I got 2 of these cases just 2 days ago (bought from banggood), used Akasa thermal tape (0.3mm, good contacts, tough bonding) with one case, other still unused.

No need worry either of 3 components to get overheated even during extreme usage.

https://m.aliexpress.com/item/32882759821.html

Image

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RaTTuS
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Re: Heatsink on the LAN Chip

Thu Aug 16, 2018 7:59 am

other aliexpress
https://www.aliexpress.com/store/produc ... 77351.html
see also geekworm
I'd get some other links but my mail is down ATM
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runboy93
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Re: Heatsink on the LAN Chip

Thu Aug 16, 2018 5:00 pm

I still prefer my main RPi 3B+ setting over that earlier cheap passive aluminum case:

Akasa aluminum case, during installation of large sticky thermal pad to bottom, I included 0.3mm thick copper shim (bought x5 set from banggood) with it, even without copper shim it hit to bottom plate, so now there is little more pressure added with copper cooling effect.

And instead of using blocks of aluminum thermal modules for CPU and USB, used these (along with akasa provided sticky thermal pads)

https://www.alphacool.com/shop/grafikka ... ack-10-stk.

They hit to top lid, but still was easy to finish build.

Compare builds:

Akasa case build (Alphacool GPU heatsinks used instead of block aluminum pieces, copper shim added to bottom along with Akasa thermal pad):

around 60-61 celcius on stress, better WiFi reception, LED lights seen!, looks better, more small "ventilation" holes, around 3 times more expensive, MicroSD card impossible to take off without tools.

Cheap aluminum case build (Akasa thermal tape used with case passive cooling):

around 65 celcius on stress, way much worse WiFi reception, LEDs not seen, simple look, cheaper, MicroSD card easy to take off.

Buphord55
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Re: Heatsink on the LAN Chip

Sun Aug 19, 2018 7:30 pm

Have you guys seen this new heat sink case yet?!

Super cool sleek case!

http://kck.st/2KjtNyU

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