Most active commenters
  • throwaway894345(3)
  • theodric(3)

←back to thread

I regret building this $3000 Pi AI cluster

(www.jeffgeerling.com)
468 points speckx | 16 comments | 19 Sep 25 14:28 UTC | HN request time: 0.422s | source | bottom
Show context
Aurornis ◴[19 Sep 25 14:52 UTC] No.45302320[source]▶
I thought the conclusion should have been obvious: A cluster of Raspberry Pi units is an expensive nerd indulgence for fun, not an actual pathway to high performance compute. I don’t know if anyone building a Pi cluster actually goes into it thinking it’s going to be a cost effective endeavor, do they? Maybe this is just YouTube-style headline writing spilling over to the blog for the clicks.

If your goal is to play with or learn on a cluster of Linux machines, the cost effective way to do it is to buy a desktop consumer CPU, install a hypervisor, and create a lot of VMs. It’s not as satisfying as plugging cables into different Raspberry Pi units and connecting them all together if that’s your thing, but once you’re in the terminal the desktop CPU, RAM, and flexibility of the system will be appreciated.

replies(11): >>45302356 #>>45302424 #>>45302433 #>>45302531 #>>45302676 #>>45302770 #>>45303057 #>>45303061 #>>45303424 #>>45304502 #>>45304568 #
bunderbunder ◴[19 Sep 25 14:55 UTC] No.45302356[source]▶
The cost effective way to do it is in the cloud. Because there's a very good chance you'll learn everything you intended to learn and then get bored with it long before your cloud compute bill reaches the price of a desktop with even fairly modest specs for this purpose.
replies(12): >>45302408 #>>45302469 #>>45302503 #>>45302550 #>>45302742 #>>45302824 #>>45303327 #>>45303352 #>>45304169 #>>45304176 #>>45304278 #>>45305010 #
1. dukeyukey ◴[19 Sep 25 16:15 UTC] No.45303352[source]▶
It's good for the soul to have your cluster running in your home somewhere.
replies(2): >>45303549 #>>45303645 #
2. ofrzeta ◴[19 Sep 25 16:31 UTC] No.45303549[source]▶
Maybe so, but even then a second-hand blade server is more cost-effective than a Raspi Cluster.
replies(1): >>45304411 #
3. NordSteve ◴[19 Sep 25 16:39 UTC] No.45303645[source]▶
Bad for your power bill though.
replies(6): >>45304383 #>>45304569 #>>45304628 #>>45304785 #>>45304792 #>>45305593 #
4. platybubsy ◴[19 Sep 25 17:43 UTC] No.45304383[source]▶
I'm sure 5 rpis will devastate the power grid
5. geerlingguy ◴[19 Sep 25 17:45 UTC] No.45304411[source]▶
Not if you run it idle a lot; most commercial blade servers suck down a lot of power. I think a niche where Pi blades can work is for a learning cluster, like in schools for HPC learning, network automation, etc.

It's definitely not suited for production, but there, you won't find old blade servers either (for the power to performance issue).

6. Damogran6 ◴[19 Sep 25 18:02 UTC] No.45304569[source]▶
I got past that back when I was paying for ISDN and had 5 Surplus Desktop PCs...write it off as 'Professional development'
7. throwaway894345 ◴[19 Sep 25 18:07 UTC] No.45304628[source]▶
What does a few rpis cost on a monthly basis?
replies(1): >>45304737 #
8. theodric ◴[19 Sep 25 18:17 UTC] No.45304737{3}[source]▶
Depends. At full load? At Irish power prices? Just the Pi, no peripherals, no NVMe? 5 units? €13/mo.

Handy: https://700c.dk/?powercalc

My Pi CM4 NAS with a PCIe switch, SATA and USB3 controllers, 6 SATA SSDs, 2 VMs, 2 LXC containers, and a Nextcloud snap pretty much sits at 17 watts most of the time, hitting 20 when a lot is being asked of it, and 26-27W at absolute max with all I/O and CPU cores pegged. €3.85/mo if I pay ESB, but I like to think that it runs fully off the solar and batteries :)

replies(1): >>45305083 #
9. duxup ◴[19 Sep 25 18:22 UTC] No.45304785[source]▶
I need to heat my house too so maybe it helps a little there.
10. 11101010001100 ◴[19 Sep 25 18:23 UTC] No.45304792[source]▶
You still pay for power for the cloud.
11. throwaway894345 ◴[19 Sep 25 18:51 UTC] No.45305083{4}[source]▶
> Depends. At full load? At Irish power prices? Just the Pi, no peripherals, no NVMe? 5 units? €13/mo.

Pretty sure most of us aren't running anywhere close to full load 24/7, but whoa, Irish power is expensive. In the central US I pay $0.14/KWh.

replies(2): >>45309663 #>>45314426 #
12. trenchpilgrim ◴[19 Sep 25 19:39 UTC] No.45305593[source]▶
Still less than renting the same amount of compute. Somewhere between several months and a couple years you pull ahead on costs. Unless you only run your lab a few hours a day.
13. theodric ◴[20 Sep 25 02:28 UTC] No.45309663{5}[source]▶
Yeah, it's brutal. Was €0.39 right after Mad Vlad kicked off his vanity conflict.
replies(1): >>45340655 #
14. fragmede ◴[20 Sep 25 15:57 UTC] No.45314426{5}[source]▶
cries in west coast peak $0.71/KWh rate
15. throwaway894345 ◴[22 Sep 25 22:57 UTC] No.45340655{6}[source]▶
That’s rough. What’s your progress on renewables? Wind has made electricity really cheap in my state and I would think Ireland would be pretty windy (esp offshore)?
replies(1): >>45483949 #
16. theodric ◴[05 Oct 25 18:30 UTC] No.45483949{7}[source]▶
Ireland has had hydro for a century[1], and wind and tidal are productive here. There are wind farms EVERYWHERE around where I live (mountains, Cork/Limerick border). There are solar farms, as well, but sun is not our strong suit. Trouble for individuals is that small, affordable wind turbines are basically useless, and most people don't have hundreds of thousands of Euros plus planning permission to erect megawatt-scale units, so solar is pretty much it.

[1] https://en.wikipedia.org/wiki/Shannon_hydroelectric_scheme