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World Community Grid Forums
Category: Community
Forum: Hardware Chat Room
Thread: surprisingly fast Raspberry Pi spotted |
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Thread Status: Active Total posts in this thread: 36
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poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges: 
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D_S_Spence, which model do you have?
----------------------------------------Looks like the 3B+ and 4B have additional throttling (temp_soft_limit) set by default... https://www.raspberrypi.org/documentation/har...i/frequency-management.md CPU times on my 3B with 32-bit Raspbian (no throttling or swap): 1 task at a time: 14.7 hours 2 tasks at a time: 14.4 hours and 17.5 hours 3 tasks at a time: between 16.5 and 18.5 hours [Edit 1 times, last edit by poppinfresh99 at May 23, 2020 4:19:29 AM] |
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D_S_Spence
Advanced Cruncher Canada Joined: Jan 5, 2017 Post Count: 118 Status: Offline Project Badges: 
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Hi poppinfresh99,
It's a 3B (not '+'). I turned it on its side last night, and it looks like it's helping a bit. Current temp is 82.7C and current speed is 961 MHz. It's running 4 Open Pandemics tasks. 3 of them look like they are expected to take less than 30 hours. The 4th one... almost 40 hours! So later, I will restrict it to use 3 cores to see what effect that has on the times. (Temp checked with 'vcgencmd measure_temp', clock speed checked with 'vcgencmd measure_clock arm'.) |
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poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges:
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D_S_Spence, do you know if you are using swap? Are you running anything else besides BOINC?
----------------------------------------There's probably a better way to check, but I use the following command... top -o %MEM though just the following should do it too... top Edit: The following command is also nice... htop [Edit 1 times, last edit by poppinfresh99 at May 27, 2020 2:11:31 PM] |
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andreba57
Cruncher Italy Joined: Apr 14, 2020 Post Count: 5 Status: Offline Project Badges: 
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I just set up a 4B just to run World Community Grid projects.
The Pi is headless, fanless, and runs Raspbian Lite (no GUI). The temp is stable at 58 C° in daytime and the clock doesn't seem to be throttled. I installed zram to save wear on the SD card, but apparently the swap file doesn't get used, at least when processing Open Pandemics work units. The command I use to check memory allocation is free As for the processing times, the first batch of Open Pandemic tasks has estimated times of about 9 hours, which is about three times slower than my laptop. Not sure on how this compares to other Raspberries, the only other Pi I have is a 1b and it definitely doesn't qualify for this sort of work. |
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poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges:
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andreba57, if these often-very-wrong estimated times ended up being the actual times (which can be seen via WCG website), you've helped me conclude that the 4B is just twice as fast as the 3B for some mysterious reason. If you're running 4 tasks, I would also conclude that the 4B runs cooler!
I would then conclude that 64-bit vs 32-bit probably has nothing to do with this 2x increase in speed between my 3B and your 4B. 64-bit Raspbian doesn't even exist! There is only a 64-bit kernel that then allows you to run systemd-nspawn to create a 64-bit OS inside of Raspbian (see raspbian-nspawn-64)... https://www.raspberrypi.org/forums/viewtopic.php?t=257767 BTW, I tried to get a 64-bit kernel on Stretch instead of Buster, and my Pi now won't boot. I do want to try a true 64-bit OS to see if there is also some speedup for that, so, once I get back into my work building to get my microSD card adapter, I want to install Ubuntu Server... https://ubuntu.com/download/raspberry-pi This should be similar to Raspbian Lite, and maybe I'll then get Lubuntu desktop via `sudo apt install lubuntu-desktop`. I need to run OpenPandemics so we can treat Covid patients so I can get access to my work building, but I need to get access to my work building to run OpenPandemics! |
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hchc
Veteran Cruncher USA Joined: Aug 15, 2006 Post Count: 865 Status: Offline Project Badges: 
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Anyone have a Kill-a-Watt power meter? I'm curious how much power your Pi 4Bs draw. I'm thinking of buying 4-7 of them and making a cluster (and getting a 5-port switch or 8-port switch, respectively).
----------------------------------------At some point it may be cheaper to just go with a single amd64 (x86-64) CPU such as an Intel Atom or one of AMD's APUs for similar numbers of cores and similar power consumption. For example, buying 4 Pi 4Bs @ $55 each + 4 power supplies, 5 patch cables, 5-port switch, 4 heat sink cases, and a cluster case is easily over $300 just for 16 cores. I could potentially buy a 4-core/8-thread AMD Ryzen 3 3100 for $99 or 3300X for $120, and both have TDPs of 65 Watts.
[Edit 4 times, last edit by hchc at May 26, 2020 3:25:42 AM] |
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D_S_Spence
Advanced Cruncher Canada Joined: Jan 5, 2017 Post Count: 118 Status: Offline Project Badges:
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poppinfresh99, I limited BOINC to 75% of CPU cores (so 3 WUs at a time), and now it reports running at 1.15 GHz (so not very throttled) and is finishing WUs in 18-19 hours, which is a lot less upsetting. It's still hot, though (over 80C).
It looks like it's not running out of RAM. Each WU is taking from 10%-13% of memory. The Pi runs Xorg and a VNC server, and I leave the BOINC Manager open, but that's about it. Of course there's a lot of other things appearing in top, but all taking very little resources. |
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mgpointner
Advanced Cruncher Argentina Joined: Nov 16, 2009 Post Count: 55 Status: Offline Project Badges: 
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The best way I find to monitor my Rasp 4b is RPI-Monitor
----------------------------------------https://xavierberger.github.io/RPi-Monitor-docs/index.html  |
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hwierzbicki
Advanced Cruncher Joined: May 1, 2016 Post Count: 55 Status: Offline Project Badges:
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Anyone have a Kill-a-Watt power meter? I'm curious how much power your Pi 4Bs draw. The RP4 consumes 7.6W at full load (link). At some point it may be cheaper to just go with a single amd64 (x86-64) CPU such as an Intel Atom or one of AMD's APUs for similar numbers of cores and similar power consumption. The RP4 may not be as powerful as some of the low-end x64 chips, but you currently can't beat ARM for core count on a budget. I could potentially buy an 8-core/16-thread AMD Ryzen 3 3100 for $99 or 3300X for $120, and both have TDPs of 65 Watts. The 3100/3300 are 4C/8T CPUs. Plus you have to factor a MB, RAM, PSU, case, etc, into the cost. Not to mention, consider the size of a full build compared to a single RP. For example, buying 4 Pi 4Bs @ $55 each + 4 power supplies, 5 patch cables, 5-port switch, 4 heat sink cases, and a cluster case is easily over $300 just for 16 cores. Sure, if you want to go all out. 1. 4GB of RAM isn't necessary and 2GB models go for around half the price of 4GB models. 2. While a switch and patch cables are nice, they certainly aren't necessary. 3. Pick up a 100W AC/DC power supply for $10-15 and you should have enough capacity for 10+ RP4. Honestly, if you want the best bang for your buck you could pick up an 8C A53 Android TV from Amazon for $30.  [Edit 2 times, last edit by cwierzbicki at May 26, 2020 2:43:21 AM] |
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poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges:
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I have a Kill A Watt (but a Pi 3B not a Pi 4B), and I find the following site accurate (see Power ratings row), and it says that max power usage for 4B is 6.25 W, but keep in mind that BOINC is probably not using a lot of Internet and is probably being used headless, so it will use a bit less than 6.25 W...
----------------------------------------https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications For the amount of work you get done, you will certainly use less electrical power using ARM than using x86. ARM is the future now that x86 can't just rush to keep making transistors smaller forever! I wonder if there is some kind of ARM CPU rack to buy ??? If you want to run Rosetta@home (instead of WCG), 4 GB of RAM can be very useful! [Edit 3 times, last edit by poppinfresh99 at May 27, 2020 2:23:26 PM] |
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