Distributed Computing on Raspberry Pi

[michalrz]

Hey! I've integrated this measuring thing of mine into my experimental solar setup, so if anyone wants a Rpi4 tweak tested feel free to let me know

 

[michalrz]

Yeah hi,
The regular Raspberry Pi lineup is completely unavailable where I live right now, so I bought two Raspberry Pi Zero 2W.
Aim was to use them for BOINC and/or CCTV.

Here's some observations (no tweaks to either):

	Raspberry Pi Zero 2W​	Raspberry Pi 4B, 4GB model​	Raspberry Pi 4B, 2 GB​
RAM​	512 MB DDR2	4 GB LPDDR4	2 GB LPDDR4
Price​	100 Złoty PLN (equivalent to like $25 USD)	400 Złoty PLN (equivalent to like $100 USD)	300 Złoty PLN (equivalent to like $74 USD)
Power consumption with 100% load - 4x concurrent World Community Grid OPN tasks​	0.5 A - 2.51W	0.95 A - 4.70 W	0.95 A - 4.70 W (assumed same based on the 4GB model)
Power consumption while idling (VNC/SSH session)​	0.17 A - 0.88 W	0.49 A - 2.45 W	0.49 A - 2.45 W (assumed same based on the 4GB model)
CPU​	ARM Cortex A53 @ 1.0 GHz	ARM Cortex A72 @ 1.5 GHz	ARM Cortex A72 @ 1.5 GHz
PPD (WCG, 10 days average)​	To be calculated, will edit it in here in a few days (temporary filler info: day 2 it's sloooow)	6394,3	6394,3 (assumed based on RPI 4GB)

The kicker is that the Zero 2W is dirt cheap.

It's around twice the price of an ESP32 TTGO development board (SD + WiFi + BT) while boasting orders of magnitude the computing power AND still managing to maintain a fairly low power consumption.

At this point, I'd have trouble deciding between a Raspberry Pico (which is supposed to compete with Arduino-like devices) and this, simply because the Pi Zero 2W is more future-proof (as in performance) and easier to get software for.

It's also very tiny, around half of the size of a Rpi4 (see attached image of test setup, gives an idea of the minuscule footprint).

 

[Endgame]

I’ve looked into the pi 0 before. You should see roughly pi 3 performance if I remember correctly. 512mb Ram means you’ll probably need to run with zram to stretch Ram enough though.

Edit to note that while per core performance is similar to the pi 3, the pi 0 only has 1 core clocked about 20% slower, so you would need 4 pi 0s for the same ppd output.

 

[Icecold]

I’ve looked into the pi 0 before. You should see roughly pi 3 performance if I remember correctly. 512mb Ram means you’ll probably need to run with zram to stretch Ram enough though.

Edit to note that while per core performance is similar to the pi 3, the pi 0 only has 1 core clocked about 20% slower, so you would need 4 pi 0s for the same ppd output.

I'm not a pi expert, but I think that was just the first version of the Pi Zero. michalrz is using a Pi Zero 2W (which it looks like is a new model that just came out within the last couple months) which is listed as the following - "With a quad-core 64-bit ARM Cortex-A53 processor clocked at 1GHz and 512MB of SDRAM, Zero 2 is up to five times as fast as the original Raspberry Pi Zero.". 512MB of RAM still though is then probably even more of an issue if trying to run 4 tasks at a time instead of 1.

 

[michalrz]

I’ve looked into the pi 0 before. You should see roughly pi 3 performance if I remember correctly. 512mb Ram means you’ll probably need to run with zram to stretch Ram enough though.

Edit to note that while per core performance is similar to the pi 3, the pi 0 only has 1 core clocked about 20% slower, so you would need 4 pi 0s for the same ppd output.

I'm not a pi expert, but I think that was just the first version of the Pi Zero. michalrz is using a Pi Zero 2W (which it looks like is a new model that just came out within the last couple months) which is listed as the following - "With a quad-core 64-bit ARM Cortex-A53 processor clocked at 1GHz and 512MB of SDRAM, Zero 2 is up to five times as fast as the original Raspberry Pi Zero.". 512MB of RAM still though is then probably even more of an issue if trying to run 4 tasks at a time instead of 1.

That's correct, it's the updated one, with a quad-core (4x 1GHz) ARM chip.
Thermally wise it behaves like a Pi4 in that it can be used without a fan, but even with a fan I'm seeing 53 and 48 degrees on my two Zero 2s.

I didn't want to bog it down with zram (yet), it's running on a lite OS, but yes the 512 MB is basically exhausted with some swapping occurring.
It does show "free" 40-60 megs of RAM, but we know how that works - it scales down buffers whilst sacrificing performance.

It is significantly slower - that much is already clear. Pics attached - they've been running for like 2-3 days now, so I'd like to wait for at least 10 days more to give them a fair chance. I'm also not commenting specifically on any boinc 'economics' of it until then.

But, again, it's really cheap and really tiny and has VERY impressive power consumption and thermal performance at lower loads.
It idled at 0.88 W, which is what my puny ESP8266 WiFi-enabled weather station consumes. A $5 ESP8266 real time chip...
I wanted an adult sized Pi4, but they're GONE

Thanks for your input guys and I'll update you in a while. Will also take it through its paces with some tweaking.

 

[Endgame]

I'm not a pi expert, but I think that was just the first version of the Pi Zero. michalrz is using a Pi Zero 2W (which it looks like is a new model that just came out within the last couple months) which is listed as the following - "With a quad-core 64-bit ARM Cortex-A53 processor clocked at 1GHz and 512MB of SDRAM, Zero 2 is up to five times as fast as the original Raspberry Pi Zero.". 512MB of RAM still though is then probably even more of an issue if trying to run 4 tasks at a time instead of 1.

Well dang - I totally missed the announcement of another pi 0.

You can fit 4 open pandemic tasks on a 2GB pi 4 without needing zram, so I’m pretty sure 512mb would work using zstd as the compression option. It’s certainly way faster than swapping to sd card.

I’m certainly interested in results.

 

[michalrz]

Here's a 10 day average PPD (13th Jan backwards)

Pi 4B 4GB​	Pi 4B 4GB​	Pi Zero 2W​	Pi Zero 2W​
​ 5834​	​ 6072​	​ 2123​	​ 2017​
4.7 W​	4.7 W​	2.51 W​	2.51 W​

The Zeroes had the advantage of more tweaking to disable memory hogs, and without those tweaks it starts to kill off selected computing tasks due to exhausted memory. Even after raising swap from the default 100 to 150 megs.

So, the initial verdict - you'd need three Zero 2Ws to match the PPD of a single RPi 4B, and it would also make them priced the same.

However, three Zero 2Ws power consumption will be significantly more than a default Pi4Bs power use. Real-estate wise, a single Rpi4B is still smaller than 3 Zeroes.

I'll be doing some more testing (zram in particular), but so far I still like the Zero 2W for the form factor, price and very low power consumption (doing non computational full load stuff).