| Index | Recent Threads | Unanswered Threads | Who's Active | Guidelines | Search |
 |
World Community Grid Forums
Category: Community
Forum: Hardware Chat Room
Thread: surprisingly fast Raspberry Pi spotted |
| No member browsing this thread |
|
Thread Status: Active Total posts in this thread: 36
|
|
| Author |
|
|
poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges: 
|
I am running OpenPandemics on my Raspberry Pi 3 (Model B). Each task takes about 18 hours. I am noticing that other Raspberry Pi's typically take slightly longer, maybe because I only run 3 of my 4 cores to prevent CPU throttling due to high temperatures (and to prevent using too much RAM).
----------------------------------------I was very surprised to see someone finish a task in 8.31 hours on a task that took me 16.38 hours (CPU time). What on Earth are they doing that I am not? Can I do it too? Some thoughts... (1) They are using Raspbian Buster (I am on a fully updated Raspbian Stretch), but I have seen others on Buster calculate a bit slower than me. (2) Could there be a FPU-sharing between cores ??? Does ARM ever even do this ??? I don't think so, but I'm running a single task now as an experiment just to be sure. Maybe memory bus is slow ??? (3) My kernel version is 4.19.66-v7+, but there's is 5.4.40-v8+. I believe the v8 to mean that they are running 64-bit Raspbian, whereas I just use the default 32-bit Raspbian on my 64-bit Raspberry Pi. Could this be the difference ??? (4) The newer Raspberry Pi 4 (Model B) has a Cortex-A72 at 1.5 GHz, whereas mine has a Cortex-A53 at 1.2 GHz. The A72 allows out-of-order execution and probably has more cache, and I read that someone overclocked the Pi's A72 to 2.147 GHz ! This could explain it!? Or maybe they are running Raspbian on another device? Thoughts? Thanks! [Edit 3 times, last edit by poppinfresh99 at May 20, 2020 1:42:35 PM] |
||
|
|
hchc
Veteran Cruncher USA Joined: Aug 15, 2006 Post Count: 758 Status: Offline Project Badges: 
|
Simplest answer is they're running newer hardware such as the Pi 3B+ or Pi 4B. Probably the 4B to explain doing the same task in half the time as your 3B. Potentially the 4B with more RAM so it would reduce using the swap file?
----------------------------------------
|
||
|
|
hwierzbicki
Advanced Cruncher Joined: May 1, 2016 Post Count: 55 Status: Offline Project Badges:
|
OPN tasks generally take 8.5-9.5 hours on my RPi 4B. I have the 4GB model at a moderate OC of 1.8GHz.
---------------------------------------- |
||
|
|
poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges:
|
Swap isn't being used.
cwierzbicki, overclocking to 1.8 GHz explains some of it (overclocking to 2.4 GHz would explain all of it!). Are you using 32-bit or 64-bit Raspbian? And how many tasks are you running at a time? When I tried 1 task at a time (instead of 3), CPU time reduced to 14.7 hours, which I don't fully understand---slow memory bus? shared cache? only having one data point? I'm curious which parts of the following affect OpenPandemics... https://en.wikipedia.org/wiki/Comparison_of_ARMv8-A_cores |
||
|
|
hwierzbicki
Advanced Cruncher Joined: May 1, 2016 Post Count: 55 Status: Offline Project Badges:
|
Running 64bit Raspbian, with WCG running on all 4 cores!
----------------------------------------Do you have a heatsink installed on your board? May be an issue with thermal throttling. |
||
|
|
gibbcorp
Advanced Cruncher Joined: Nov 29, 2005 Post Count: 76 Status: Offline Project Badges: 
|
Not really related to your issue but this might interest you. :)
https://hothardware.com/news/axiomtek-raspberry-pi-rival-flexes-amd-ryzen |
||
|
|
poppinfresh99
Cruncher Joined: Feb 29, 2020 Post Count: 49 Status: Offline Project Badges:
|
Interesting. I should experiment by switching to 64-bit.
----------------------------------------No throttling. I can be sure by using the commands... vcgencmd measure_temp vcgencmd measure_clock arm I do have a basic heat sink (and it's oriented for best convection when Pi is placed on its side as it should be), but I need a fan. With 3 cores running, I am at 75 °C. Minor throttling at 81 °C if I run 4 cores depending on room temperature. Edit: Oh, we were posting at the same time gibbcorp. That board looks neat. I bet you could use its GPU for BOINC? I like boards like the Pi that have an ARM processor, which I believe to be the future! [Edit 1 times, last edit by poppinfresh99 at May 21, 2020 1:56:45 PM] |
||
|
|
hwierzbicki
Advanced Cruncher Joined: May 1, 2016 Post Count: 55 Status: Offline Project Badges:
|
I'd say it's worth it to switch! Here's some good articles about performance gains:
----------------------------------------RP3/3B: https://www.researchgate.net/publication/3246...arks_and_Stress_Tests#pf2 RP4B: https://medium.com/@matteocroce/why-you-shoul...aspberry-pi4-bd5290d48947 |
||
|
|
D_S_Spence
Advanced Cruncher Canada Joined: Jan 5, 2017 Post Count: 107 Status: Offline Project Badges: 
|
Wow! My Pi 3B is taking a glacial ~32 hours to complete these units! One wingman did one in 8, others are still waiting to be validated (so maybe those are even slower?).
My Pi is heat throttled to about 60% right now. I have a basic little heat sink on the CPU but the machine is lying flat. I'll have to experiment a bit to see if I can improve this poor performance. |
||
|
|
KerSamson
Master Cruncher Switzerland Joined: Jan 29, 2007 Post Count: 1671 Status: Offline Project Badges: 
|
Currently on a RPi 2B, with only 3 cores (avoiding throttling), the tasks take between 26 and 32 hours each, no swapping.
----------------------------------------Yves |
||
|
|
|