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4 x Raspberry Pi Cluster on Hardforum

Posted: Fri Apr 16, 2021 9:17 am
by Icecold
There's a 4 x Raspberry Pi cluster that is setup to be POE and has a POE switch on Hardforum for $550 if anybody is interested. I made an offer of $400 but it was too low. It's a pretty sweet setup though - https://hardforum.com/threads/fs-4x-rpi ... h.2009445/

@endgame124 any input on if that's a good price?

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Fri Apr 16, 2021 11:27 am
by Skillz
I think you could buy that setup new for about $600.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 12:29 am
by endgame124
It’s probably a touch expensive, at least if you have a microcenter nearby. They are always running $5 off or $10 off specials on pi 4s.

If you’re doing distributed computing on those pis, you really want better airflow - both the poe hat and the pi itself will have stability issues at 100% load without airflow

Then we need to talk about the size of the pis - there are only 2 projects that will use more than 2GB of memory on a pi 4. Folding at home and Rosetta. With the right zram configuration, a 4gb pi is fine for Rosetta, and forget about F@H - you’re better off running a bulldozer with some silly inefficient video card in points per watt than a pi 4.

Depending on technical skill, I wouldn’t recommend the flash cards either. Network boot the pis, or at least use a network share for the WUs.

If I were to build another pi cluster, I would probably get a 12 pi stacking case, a 12 port PoE switch with uplink, and do 6x 2GB pis and 6x 4gb pis. I would put 4 2GB pis full time on open pandemics, 6 4GB pis on Rosetta, and then put one 2GB on asteroids and 1 2GB pi on Einstein. Everything would have open pandemics as a fall back project.

Prices estimate, not counting poe switch and cables would be about 750.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 9:43 am
by Skillz
I really need to build a Pi cluster.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 12:12 pm
by endgame124
Skillz wrote: Mon Apr 19, 2021 9:43 am I really need to build a Pi cluster.
Do it for fun, but it has limits for power efficiency (5950 or EPYC is certainly more efficient). Managing all the systems is also a little annoying, but that’s really limited to working with Rosetta on 4GB pis. About once every other month, one of them will crash because it was allocated WUs that are non compressible and too much ram is allocated. It’s fantastic for replacing old hardware though - 2 pi 4s put out more ppd than my core 2 quad or my old APUs and they use a small fraction of the power for like $50 invested.

I highly suspect that my setup could become more power efficient with the right PoE switch, but I didn’t want to put in the effort to find the right switch. If you could find a switch with a power supply equivalent to a titanium PSU you would pickup around 15% better points per watt and possibly surpass a 5950 in eco mode, but you still wouldn’t pass an EPYC box.

Really what I need is someone to pay me to figure this all out, then I would be much further along.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 12:20 pm
by Skillz
How much will it cost? Lol

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 12:29 pm
by endgame124
Skillz wrote: Mon Apr 19, 2021 12:20 pm How much will it cost? Lol
Cheapest possible config, or 1 pi 4 setup to play with?

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 12:46 pm
by Skillz
To learn the optimum setup for points/watt.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 1:05 pm
by endgame124
Skillz wrote: Mon Apr 19, 2021 12:46 pm To learn the optimum setup for points/watt.
basically, my recommended parts list for learning (or making a Kodi box) is:

4GB Pi 4
FLIRC Raspberry Pi 4 aluminum case
32GB Samsung Select Micro SD card
Official Raspberry Pi 4 power supply
Ethernet cable

Total Cost: ~$90

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 4:19 pm
by StefanR5R
If you consider Raspberry Pi 4 for experiments in power efficiency, keep in mind that its processor is on a 28 nm node. Its efficiency is saved by the slow clock (1.5 GHz) and by the SBC's minimalism.

Regarding a stack of these, wouldn't a DIY power supply be not only much cheaper than a PoE solution, but potentially more power efficient too?

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 4:50 pm
by Icecold
If there were even a single project known to work on the GPU cores, I would really like to pick up an NVidia Jetson Xavier board to test out. Its CPU should be built on a 12NM node - https://www.anandtech.com/show/13584/nv ... and-more/3

An Nvidia Jetson Xavier is $400 USD, so quite a bit more than a raspberry pi, but the processor should be much faster, and the GPU should be decent, it just doesn't work on any projects AFAIK.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Mon Apr 19, 2021 5:00 pm
by endgame124
StefanR5R wrote: Mon Apr 19, 2021 4:19 pm If you consider Raspberry Pi 4 for experiments in power efficiency, keep in mind that its processor is on a 28 nm node. Its efficiency is saved by the slow clock (1.5 GHz) and by the SBC's minimalism.

Regarding a stack of these, wouldn't a DIY power supply be not only much cheaper than a PoE solution, but potentially more power efficient too?
DIY 5V power supply is a double step beyond anything I have the time and patience to do. Would love to see results from someone who tries it.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Tue Apr 20, 2021 2:30 pm
by Icecold
I have 3 of these kits and bought them from this seller - https://hardforum.com/threads/fs-raspbe ... 1044993430

It took awhile to get, but it was when the US had real bad weather, so I don't fault the seller and once I got them they were as described. They had sd cards with a fresh load of Raspbian so I just installed BOINC, configured everything, disabled the GUI and they seem to be working fine. They just dropped the price, it seems like a solid deal. They are kind of loud(You can connect the fan to a lower voltage pin on the Pi I'm pretty sure to lower the RPM's), but they're drowned out by the 8 other pc's next to them :lol:

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Tue Apr 20, 2021 10:15 pm
by endgame124
Icecold wrote: Tue Apr 20, 2021 2:30 pm I have 3 of these kits and bought them from this seller - https://hardforum.com/threads/fs-raspbe ... 1044993430

It took awhile to get, but it was when the US had real bad weather, so I don't fault the seller and once I got them they were as described. They had sd cards with a fresh load of Raspbian so I just installed BOINC, configured everything, disabled the GUI and they seem to be working fine. They just dropped the price, it seems like a solid deal. They are kind of loud(You can connect the fan to a lower voltage pin on the Pi I'm pretty sure to lower the RPM's), but they're drowned out by the 8 other pc's next to them :lol:
The price isn’t bad, but the cheap fan in those cases has like a 6 month life span. For stand alone pis i really think the Flirc case is worth the extra for the ability to run passive.

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Tue Apr 20, 2021 10:45 pm
by Icecold
Interesting, I didn't know the fans were that bad. Maybe in 6 months if they start to fail it'll be a good time to buy another Pi and put them all in a 4x Pi case like this one - https://www.amazon.com/GeeekPi-Raspberr ... B083FDHPBH

Re: 4 x Raspberry Pi Cluster on Hardforum

Posted: Tue Apr 20, 2021 10:58 pm
by endgame124
Icecold wrote: Tue Apr 20, 2021 10:45 pm Interesting, I didn't know the fans were that bad. Maybe in 6 months if they start to fail it'll be a good time to buy another Pi and put them all in a 4x Pi case like this one - https://www.amazon.com/GeeekPi-Raspberr ... B083FDHPBH
The Geek pi stacking case like that is really nice. I have the 8 stack version.

Hopefully the little fans in yours work well and don’t crap out as fast as mine did.