On Tue, Apr 03, 2018 at 10:33:12AM -0400, Adam Holt wrote: > On Mon, Apr 2, 2018 at 12:36 PM, Adam Holt <[1]h...@laptop.org> wrote: > > On Mon, Apr 2, 2018 at 10:44 AM, Adam Holt <[2]h...@laptop.org> wrote: > > 1) Recap from 2016: heatsinks on the original RPi3 CPU are not a > cure-all when the RPi 3 is enclosed in a case that lacks ventilation > on > a hot day. But CPU heatsinks Do Work when taking the plastic top off > the of the original RPi 3. The CPU throttling problem "immediately" > goes away on such hot days...bringing the temperature back down below > 80C...as measured by the command: > > vcgencmd measure_temp > > 2) It's snowing today right outside my window, so I can't easily > simulate a hot summer's day -- but can others who live in hot > environments report back their readings above, when running the new > RPi3 B+ in various conditions? > ☆ With heatsink on CPU -- and without? > ☆ With motherboard fully enclose by a case -- and without? > > My own results, with all 4 CPU's unloaded, in a chilly room: > > RPi 3 with-heatsink-on-CPU / RPi 3 B+ / RPi 3 B+ with-heatsink-on-CPU > 44-46C / 46-48C / 45-47C case's plastic top removed (w/o wind or active > ventilation) > 46-49C / 48-51C / 48-52C case's plastic top attached (contains 100+ small > holes > on 1 end, allowing very little ventilation) > > After I ran "yes > /dev/null &" 4 times, to fully load all 4 cores of the > CPU: > > RPi 3 with-heatsink-on-CPU / RPi 3 B+ / RPi 3 B+ with-heatsink-on-CPU > 80-82C / 70-71C / 71-72C case's plastic top removed (w/o wind or active > ventilation) > 82-84C / 75-78C / 79-82C case's plastic top attached (contains 100+ small > holes > on 1 end, allowing very little ventilation) > > RESULT: attaching a heatsink to the RPi 3 B+ CPU does not help. It might even > make things a bit worse, hmm.
Yes, your heatsink is no good. The B+ CPU has a heatsink or heat spreader already, that silver coloured bevelled structure with the black dot and Broadcom logo. What is the shape, size, and attachment method for your added heatsink? > In any case: this result is completely different the original RPi 3 (where > past > experiments have shown that a heatsink-on-CPU greatly lowers its temperature, > When The Case Is Open!) > > > CONCLUSION: the RPi 3 B+ appears to be a real winner in CPU-intensive > conditions, even in a "wintry" conditions (room is about 15C, and it > continues to snow right outside the window). The RPi 3 CPU is supposed to > self-throttle at 80C, until it just about turns itself off at 85C. I'd > assume the RPi 3 B+ CPU does the same? But do not know for sure. Thanks > to all who can add any similar data points, in warmer climate/conditions. > > CLARIFS: Both RPi's were running a near-final prerelease of > Internet-in-a-Box 6.5 on Raspbian Lite to explore real-world conditions. > I waited 10+ min in all above 8 experiments before taking "steady state" > temp readings. Still, fluctuations in CPU activity (and temperature) > arise, even long after I ran "killall yes" to end the most intensive CPU > activity. > > 3) Prelim thermal analysis of RPi 3 B+: > > [3]https://cdn-images-1.medium.com/max/1600/1*0jU89Yu_6miI-CODB > MuHAw.png > [4]https://medium.com/@ghalfacree/benchmarking-the-raspberry-pi > -3-b-plus-44122cf3d806 > > -- > [5] > [6]Unsung Heroes of OLPC, interviewed live @ [7]http://unleashkids.org > ! > > -- > Unsung Heroes of OLPC, interviewed live @ [8]http://unleashkids.org ! > > > References: > > [1] mailto:h...@laptop.org > [2] mailto:h...@laptop.org > [3] https://cdn-images-1.medium.com/max/1600/1*0jU89Yu_6miI-CODBMuHAw.png > [4] > https://medium.com/@ghalfacree/benchmarking-the-raspberry-pi-3-b-plus-44122cf3d806 > [5] > https://medium.com/@ghalfacree/benchmarking-the-raspberry-pi-3-b-plus-44122cf3d806 > [6] > https://medium.com/@ghalfacree/benchmarking-the-raspberry-pi-3-b-plus-44122cf3d806 > [7] http://unleashkids.org/ > [8] http://unleashkids.org/ > _______________________________________________ > Server-devel mailing list > Server-devel@lists.laptop.org > http://lists.laptop.org/listinfo/server-devel -- James Cameron http://quozl.netrek.org/ _______________________________________________ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel