Yes, there probably is heat conduction through the backside of the cpu chip through the motherboard substrate. The gpu chip is closely opposite the cpu chip. The gpu chip did get its own heat sink in the case package.

I don't normally have the Manager running, only when I want to set logging options or computing preferences. The gpu just has to paint a static desktop image. The display is blanked after the standard five minutes I think. I never looked at that or changed anything from default. BoincTasks suffices for daily monitoring with all the farm rigs.

I saw others in this thread mention running tasks on all four cores. Does that 100% loading affect compute times like a 100% loaded PC cpu? I just set it to 50% because that is approximately where I set my PC cpus. I don't have any familiarity with ARM processor cpu or thread scheduling.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

No accurate metrics from me, just a "well calibrated finger tip".
My RPi will run four at a time, but gets hot very rapidly (fails the 5 second test), so I run 3 (real cores, no hyper-threading here) and it passes the 5 second test.

It will be interesting to see what happens when the fan arrives (should have been here today, but Parcel Farce failed again).

(For the uninitiated - not you Keith as you probably already know this one - the five second test is can you put the tip of your finger on the thing for a few seconds without saying "Ouch that's a tad warm")

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

My RPi 3B+ is running 4 tasks and is usually at 45 degrees.

I have a USB fan on the side of it, and it has this heat sink:
https://www.adafruit.com/product/3082

My older models run hotter with just 2 tasks running, with a smaller heat sink and other combinations of cases (case with a fan in it, a flirc case case 2 of them).

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~Chris

Those are great times for all four cores in use. Good and acceptable temps too. Maybe my concern of overloading the cpu is not valid. Your compute times running 4X are better than mine running 2X.

Can I assume you are running stock clocks at 1.4Ghz? That is what mine run at and I get an error message that my cpu is not overclockable when I choose the overclock selection in raspi-config.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Thanks, Rob. I am worried that the big chip on the bottom side of the board, guessing that is the gpu, would be at a disadvantage for having trapped air and no airflow from the little fan blowing on the cpu heat sink on the top side of the board. There are little rubber nubbin feet on the case to give about 1/4" of clearance so only convection cooling on that chip.

Hi Keith,

The chip on the bottom is the RAM chip I'm not sure there is actually a GPU chip, the 3 on top are CPU, LAN and wireless. The cases I got for my Pis come with a fan and 3 heat sinks. There's a copper sink for the RAM chip, it has no fins, the other 2 are the aluminum ones with fins.

Have a great day! :)

Siran

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CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Thanks Siran. I never bothered to inspect the lettering on the die on the bottom before slapping the heat sink on it. If I had I probably would have recognized a memory manufacturer. I too had 3 paste on heat sinks. Two large pin grid sinks for the cpu and memory dies and a smaller finned heat sink for the LAN chip. Thinking about the definition of a SoC for a minute, I should have realized the gpu is embedded into the cpu die.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Thanks Siran. I never bothered to inspect the lettering on the die on the bottom before slapping the heat sink on it. If I had I probably would have recognized a memory manufacturer. I too had 3 paste on heat sinks. Two large pin grid sinks for the cpu and memory dies and a smaller finned heat sink for the LAN chip. Thinking about the definition of a SoC for a minute, I should have realized the gpu is embedded into the cpu die.

Hi Keith,

No problem! My pleasure. It's nice to help others for a change. :)

Have a great day! :)

Siran

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CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Eh?????
My case & fan turned up today. Parcel Farce must have had a "strange turn" as the parcel wasn't due until Monday

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Eh?????
My case & fan turned up today. Parcel Farce must have had a "strange turn" as the parcel wasn't due until Monday

Not Pi related, but more than one time I ordered something for work in the morning, slow free delivery and zap, it arrived the same afternoon. Most recently however the same delivery company lost a shipment. Stuff happens.

Those are great times for all four cores in use. Good and acceptable temps too. Maybe my concern of overloading the cpu is not valid. Your compute times running 4X are better than mine running 2X.

Can I assume you are running stock clocks at 1.4Ghz? That is what mine run at and I get an error message that my cpu is not overclockable when I choose the overclock selection in raspi-config.

Yes, running my 3B+ at stock clocks. But after watching the below video where it shows how to modify config.txt, I may kick it up to 1.5 Ghz this weekend.

https://www.youtube.com/watch?v=SWl0n-uNdLc

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~Chris

Thanks for the video link Chris. Pushed my Pi 3+ to 1.5Ghz. So will run Seti for a bit and see whether it is stable. The sysbench calculate of prime ended up at 51°C. after five minutes. About 7°C. hotter than at stock. Seti at two tasks is only at 45°C. or about 2 °C. hotter than the stock 1.4Ghz.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I pushed the cpu core usage up to 75% but then had unrecoverable errors on all three tasks. Temps were still in the 50°'s C. but too much I assume for the 100Mhz overclock on the cores. Backed down to 50% usage.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Question for the Pi types. Has anyone done a comparison on the RAC between a Pi3B running 32 bit o/s and running a 64 bit O/S?
Just wondering if it is worth the time to set up.

I've been at 1.45 GHz on my 3B+ for the last 36 hours. No issues with that so just pushed it up to 1.5 just over an hour ago. Still running 4 tasks.

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~Chris

I was running +100Mhz on both cpu and gpu. Compute errors after about 60 minutes which trashed the other two initial tasks that were running OK on that overclock. Did you overclock just the cpu Chris? I am wondering if pushing both was what made the Pi3B+ unstable.

[Edit] Also another question. What version of Raspian are you running. Lite, Desktop or Full?

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I pointed another PI user over here. He is asking about "running graphics" on his PI.

Tom

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A proud member of the OFA (Old Farts Association).

Was that Tony?

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I pointed another PI user over here. He is asking about "running graphics" on his PI.

Tom

Hi Tom,

Wouldn't there be an app for doing WUs on the GPU? I'm assuming there is none. Every Pi I have looked at on accounts here have no GPU listed. I believe it's like Keith said the other day that the GPU is part of the CPU, if I understood him correctly. ;) There is no "dedicated" GPU chip that I know of.

Have a great day! :)

Siran

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CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

My Aarch64 processor rev 4 (aarch64) running Android 7.1.1 has an embedded GPU OpenCL GPU Mali-671 (4096 MB) driver 1.02 but SETI@home is not using it. Einstein@home does not even recognize it.
Tullio

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I pointed another PI user over here. He is asking about "running graphics" on his PI.

Perhaps he meant the screensaver, which as far as I know does not exist in Linux