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Message boards :
Number crunching :
rosetta@home on raspberry pis?
(Message 5236)
Posted 29 Mar 2022 by franz Post: Hello, I used to run Rosetta@H on my RPI4 / 8GB before they ran out of tasks. In was OK, no issues. For Rosetta & RPi4, my tip is: underclock the CPU. It's limited by DDR speed, high CPU clocks only raise power usage without much real benefit (ok, there might be some small benefit, but i'm a sucker for efficiency). The opposite is true for U@H, it's pretty much frequency limited. Tips for increasing U@H productivity: make sure you're using a recent linux distro. In particular, newer glibc versions (2.29+) have updated math library with ARM optimizations. This has moderate effect on RPI 3 at least, with RPI 4 the effect is smaller, AFAICT. |
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Message boards :
Number crunching :
Pi Autoshifter
(Message 5235)
Posted 29 Mar 2022 by franz Post: I have 4 odroids and 2 raspberrys; i thought i'd chime in about my own experience with running BOINC on them. First, with BOINC, in my experience much better (more efficient) to use all CPU cores at low frequency, than to use less cores at high frequency, because power efficiency goes down with rising frequency. I don't know why OP had problems with limiting frequency, maybe he was trying to do it with hardware limiting; you only need to limit the linux kernel scaling frequency, there's no need to mess with hardware limits. It's as simple as this: for F in /sys/devices/system/cpu/cpu?/cpufreq/scaling_max_freq ; do echo MAX_FREQ >$F ; done ... where MAX_FREQ is the desired max frequency in kilohertz. Also i must disagree with OP saying that little heatsinks only help a for a few minutes. They help a lot, even the small ones, but only if air can move through them easily; if the whole Pi is in a box without holes, any heatsink will be useless. It's also likely that hats will limit the airflow. I have a RPi3 outside, with a small aluminium heatsink (from transistor), no hats, only some sensors via GPIO. It's limited to 1000 Mhz, running U@H on all cores, with ambient -2 to 10C (winter) it runs at around 40-45C, no throttling. RAC is around 5000 (U@H tasks only). At summer it gets much hotter and starts throttling, so i underclock it more. I can't compare RPi2 vs RPi3 as i don't have the RPi2. But RPi4 is no contest; it's significantly faster, with the same 1000Mhz it's about +50% RAC at U@H, with similar heat output. And as for the "80C is alarming to people..." : that might be true, but only for people who have no insight into electronics. Most electronic components are rated for 100+ C; some transistors are even rated 150+ C. Pretty much all x86 laptops sold today (and past years) have throttling set to 100C. So 80C on RPi is perfectly safe. As for longevity, 80C might affect it, but not longevity of the CPU; more likely with capacitors. More damaging to CPU than 80C is frequent temperature cycling (going hot-cold-hot-cold etc). Ofc you might want to reduce temp for other reasons (cost and/or efficiency). |
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Message boards :
Number crunching :
Double your task throughput on Linux
(Message 5199)
Posted 26 Mar 2022 by franz Post: Keith: FWIW, on Linux part of glibc is called "libm", a math library, and the Universe app uses math functions from it (quite heavily). Every now & then the math functions in libm get updated with new more optimized versions that are faster. That's why you see improved times with newer glibc versions. Windows probably doesn't bother with providing any optimized versions. |
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Message boards :
Number crunching :
Howto for aarch64 machines (ODROID C2, Pine64, Banana PI HC5...)
(Message 4971)
Posted 2 Dec 2021 by franz Post: can you try launching the binary directly ? as in, from command line, run /var/lib/boinc-client/projects/universeathome.pl_universe/BHspin2_19_arm-unknown-linux-gnueabihf (adjust if your boinc is not in /var/lib) does it print anything useful ? |
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Message boards :
Number crunching :
Howto for aarch64 machines (ODROID C2, Pine64, Banana PI HC5...)
(Message 1890)
Posted 17 Jan 2017 by franz Post: That's nice, but not very useful. On ODROID C2 I can simply install boinc-client and boinc-manager via apt. What i'd be interested in, is how to compile the universe app itself for aarch64. Currently when i look at it:
it says
... so basically it's a 32bit executable pretending to be 64bit. Nice but not the best. NEON in ARMv8 a) has 2x more registers, b) is 754 compliant, c) has vectors with double elements. A properly optimized binary for ARMv8 would be much more useful, but i guess that's going to take a while... |
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