Is there a computer I can power via PoE?
Comment on Can a Raspberry Pi 5 with 8 GB of RAM handle my needs?
towerful@programming.dev 10 months agoI agree.
Pis are great for tinkering, GPIO things, or ultra low power.
Plenty of older hardware out there that is as powerful (or more so), more reliable (ie, not an sd card), and more maintainable (ie can swap CPU/ram/disks/fans/psu).
But, power consumption is always a concern. At $0.30/kwh, 10 watts is $27 per year.
So, if a pi draws 5w and an SFF draw 25w, thats $55 per year. Any price benefit of a larger/older PC is negligiable after a year or 2, so reliability probably wont come into it.
AtariDump@lemmy.world 10 months ago
towerful@programming.dev 9 months ago
A quick google found things like these:
things-embedded.com/us/…/poe-computers/Obviously tailored more to the industrial/automation/embedded side of things with odd IO. And probably a ridiculous prolice tag.
PoE++ (802.3bt) can deliver 60w. UPoE extends this to 100w. So, there is a LOT you can power from that!AtariDump@lemmy.world 9 months ago
Neat, and agreed that the price is probably stupid money.
With that in mind, it’s why I like the Pi for smaller projects - I can power them via PoE.
BigMikeInAustin@lemmy.world 10 months ago
The last video from “hardware haven” I saw (not the last released, just the last I saw) found:
Fuzzy memory on details: a 5th or 6th gen Intel idled at 7 watts vs an ultra efficient at 5 watts. He calculated out that it would take 2-4 years, depending on your electricity, to pay for the cost difference of a new ultra low power machine. CPUs and even graphic cards have gotten much better at idling very low.
towerful@programming.dev 9 months ago
5th and 6th gen are pretty ancient.
An i3-12100 motherboard bundle is about £160, will idle with dual NVMes about 20w, and will absolutely slay a similar 5th or 6th gen low power build.
Anyway…
A Pi 4 will idle around 3 to 4 watts, and run 6 watts when the CPU is pegged. A Pi 3 is 2w idle and 3.6w pegged. (ecoenergygeek.com/raspberry-pi-power-consumption/)
Here is a low power 6th gen intel build.
mattgadient.com/building-a-low-power-pc-on-skylak…
Idle draw is 10w. Total pegged draw is 50w.
They mention an i7-6700t has lower TDP (35w), so that power draw under load would be probably 25-30w.
Which is still 2x higher at idle, and 5x higher under load than a raspberry pi.
Chances are the i7 would run closer to idle when tasked with work that would be stressing the pi, considering it is twice the clock speed and twice the thread count. So, maybe 2x more draw on average (6w vs 15w)?
As for costs, im seeing i7-6700t selling used for £60, new DDR4 is probably another £40, and a new cheap motherboard is £60. A quick ebay search shows refurbbed " i5 6th gens" (no model number) with 8gb of ram and 256gb ssd going for £140 (16gb of ram is £5 more, but for the sake of comparison).
I can buy a 8gb pi4 starter kit for £104 (psu, case, sd card, hdmi cable & pi4 8gb).
Which is cheaper than a refurbished i5 6th gen, and is lower power.
If i was running virtualisation, i would absolutely pay more for something i can eventually stuff 64gb (or more) ram into, as well as multigig/10gb networking.
But for running some home services in a docker compose stack? A pi4 is going to be cheaper in the short and long term.