
Do you suffer from low magnitude disorder? Are you tired of only earning 6 Gridcoins per day? I too was once a victim of this hideous malady. But I finally said “ENOUGH IS ENOUGH!” and chose to unleash the hidden power contained within my hard earned stacks of fiat, perhaps altering the course of my entire life.
Welcome to part one of the multi-part series, I Just Wanna BOINC!, where you can follow along with my transformation from a low-mag nobody to undisputed Gridcoin royalty! (or at least to a slightly higher-mag nobody)
Part 1: The Pi Stack
Pi’s are cute, right? So why not stack a few up and start crunchin’ some goddamn work units?!
Sure, no one seriously constructs workstations out of Raspberry Pis, so the price I’m paying on a per-mag basis would surely be beaten elsewhere without much effort. But, the truth is, (a) everything isn’t all about absolute value, c’mon guys (just ask my hero, the water-cooled GPU god also known as Vortac), (b) I didn’t do any research before I ordered them so please don't judge me too harshly, and (c) I ordered 8 Pis and received 9! Thanks Amazon! This will help out a little.
This project ended up being very straightforward. I’m not much of a command line kind of guy, so they’re all running Noobs with the full GUI. I just peek in from time to time with my laptop via RealVNC.
I had awful luck overclocking an older Pi (constant freezing, poor performance, and one incident that somehow fried the SD card), so these are all currently running at stock speeds. I may get in there and experiment later, but stability is important to me. I want these to crunch for months at a time without having to intervene.
To get a feel for the relative magnitude, I pointed 4 of the Pis toward Yoyo@home (which my old Pi 2 had already been crunching for over a month) and the other 5 toward Universe@home. These seemed to be the only whitelisted projects supporting Linux on ARM that don’t compete alongside GPUs (if Enigma@home makes a return to the whitelist we'll have a third option). After a few days, I found that Universe@home was returning more than double the magnitude as Yoyo@home; therefore they’re now all running the former (this was not an effect of the increased Yoyo@home competition during the BOINC Pentathlon).
[EDIT: There seem to be additional non-GPU projects that you can crunch with Raspberry Pis (and other single board computers); e.g. many of the projects that support Android.]
I felt a twinge of guilt while selecting the Yoyo@home project and clicking the "no new tasks" button (mostly because the admin is such a cool dude; go ahead and have a listen for yourself), so I decided to write a letter to help process my feelings:
Dear Yoyo,
I’m not saying goodbye forever, I’m only saying goodbye for now. I’ll never forget all we’ve been through. I know it's painful, but try to be strong.
With Love,
jimbo88 :'(
Picture Time!
I had to wait a while for the standoffs to arrive, so here's a shot of the temporary Pi Rack (9 Pi 3s in a row, with my old Pi 2 up top):

And here's a few shots of the Pi Stack in its final form:


SD cards are easily accessible.

It does its work in the corner, under a lamp, next to the lonely-looking Pi 2.
If you look closely you'll notice that the Pi Stack is a little bit taller than the fans. This is because I was planning for 8 Pis instead of 9. But it doesn't seem to matter very much as there is still some air movement over the topmost Pi. To fasten the Pis to the base, I drilled holes and threaded machine screws into the underside of the first layer of standoffs. The USB hub and the fans are stuck to the base with Velcro, so they're secure but still easily adjustable.
Without fans, these were running just north of 80°C (green numbers):

With a few cheap fans, they are running much cooler:

Note the whacky CPU usage on Pi #1. I think this must have been the extra one that Amazon threw into the box. Maybe instead of throwing away a bad batch, they decided to give them away for free. I put this ugly duckling on the very top of the stack because its lower performance results in lower temperatures. Also note, Pis 6, 7, 8, and 9 were running Yoyo at the time of this screenshot. Universe@home seems to literally be the cooler of the two projects (by 5-10°C).
Here's the BOM:

The $80 USB hub was a bit of a torch. I could have gotten by much cheaper with a few power strips and the standard micro usb wall plugs. Or, if I actually knew what the hell I was doing, I could have powered them through the GPIO pins. No matter how you slice it, I definitely didn't get the maximum value out of my money.
And finally, here's a look at some quick and dirty ROI math:

Frequently Asked Questions (that no one has ever asked me)
Q: You know that mining some other coin might actually make you a profit, right?
A: As of right now (given my power cost) it actually is profitable to mine GRC!! But, I'd continue BOINCing even if all of GRC's value evaporated overnight. Science is cool!
Q: How many computers are too many computers?
A: I’m not really sure yet. Everything will need to fit into my tiny apartment and not be very loud, so I can’t go too crazy with this new hobby.
Q: Why must you destroy BOINC by monetizing it with your fake money crypto thing?
A: I’m always perplexed when I come across bitter comments directed toward Gridcoin from (a tiny minority of) long-time BOINC users. I’m fairly new to both of these communities, but every Gridcoin development discussion that I’ve come across seems to hold the long term success of BOINC as a core value (e.g. improving BOINC security, promoting BOINC to new audiences, brainstorming new BOINC projects, developing relationships with the BOINC admins, etc…). When it comes to the topic of decentralized currency, whether you think it’s awesome or think it’s a scam, you have to admit that it does indeed exist. There are hundreds of these currencies and the vast majority of them (Bitcoin is the best example) piss away huge amounts of computing power on pointless tasks. The goal of Gridcoin is to divert these wasted resources toward BOINC, i.e. science wins. What’s not to like?
Q: I live in Reno and I have way too many Gridcoins, can you help me?
A: Yes, I'd like to buy (with cash) another ~$1,000 worth of GRC. The Coinbase fees and delays are kinda ridiculous and the exchanges don't exactly inspire feelings of trustworthiness, though I will use them if I have to. It reminds me of the early days of online poker; you keep the absolute minimum funds on their websites because you expect to get screwed at some point, and if something bad does happen you have zero recourse.
Q: What is your crypto investment strategy? Do you have any hot tips?
A: I think that drawing shapes on graphs to try to predict the future is silly. Find a project that you believe in and buy (and mine) and hold. I would sell some (so I could sleep at night) if the price happened to go way up and the value of my GRC represented a significant portion of my net worth.
That's all for now, thanks for tuning in. The next installment of I Just Wanna BOINC! will feature a Dual CPU Z620 Workstation (and me fumbling my way through ubuntu for the first time)! You can follow along with my Gridcoin statistics here.