Edit: I'm on Linux
Edit 2: B550 AMD chipset

I am seeding from an AMD Ryzen 7 5700G system and with all the peripherals turned off and disconnected, instantaneous load was about 65 watts, until I undervolted it (negative 30, all cores), after which it has been fluctuating around 60 watts.

I'd like to keep seeding indefinitely - of course, my all time share ratio is at around 12 for now - but I'd like to use less energy and spend less money on it - even though the cost difference will be negligible, I guess.

Questions

1. Do you have any recommendations on what hardware to switch to?
2. Or any suggestions on further tweaking the power setting's in the BIOS? For now, I'm using AMD's AI solution for undervolting (PBO or Curve Optimizer or whatever it's called?), but there is for instance also the actual overclocking menu, which would force settings on the CPU.
3. What do you think about putting a single board computer inside my desktop (the chassi is HUGE) and somehow hooking up my four 4TB 2.5 inch torrenting SSDs to it? Possibly still powering them with my desktop's PSU? And running the client (qBittorrent) on the SBC?

The most cost-effective solution will always be a SBC NAS, as those bad boys just sip on power. However, there is a tradeoff - if your computer is being used as a media server, having higher end hardware means better transcoding performance.

In the bios, there should be an option called "Eco mode". Make sure you have that turned on, if that is an option. Not sure if it's different for the Ryzen chips with integrated GPU.

Finally, if you are using Windows, you'll probably get better power efficiency by switching to Linux. But I'm not sure how much.

Replace the four drives with one big nvme or sata M.2 drive and attach it to a low-power sbc.

You might be able to run the sbc inside the chassis, but since the PSU will be on you won't be saving any power there.

I don't know how to do this on AMD boxes but there are tools out there to adjust CPU power limits without undervolting, it uses the chip's built-in ability to throttle itself. I've had to do the reverse on a Dell which limits itself to 0.8GHz on any non-genuine™ power adapter, but in that case I limited the (Intel) CPU's PL2 (long-term power limit) to 25W rather than its spec 35W to save power. It thus keeps itself throttled below 25W consumption by the CPU.

I'm sorry I can't be more helpful with names of tools to try, but I just packed up all my gear to head across town, I'll try to come back and drop some URLs later. I have a little 5750GE box so I'm interested in whatever the solution turns out to be.

Also there are some good 5825U boxes out there, but it's still more oomph than you need for seeding.

I'd love to switch to a bigger ssd, but these 4TB ones already cost me 400 bucks each... :(

Interesting about the PSU! I thought it only every output/draw as much as its "clients" demanded? Is there such a big "overhead" it whatever? :O

Hah! I never even thought about these mini computers. There is a great second hand retailer of these in my country. I'll check it out! :)

Thanks! I never thought of actually downclocking instead of undervolting. No rush! :)

Right! I've seen those. "Something something compliant" and "something something rated". Although not "something something dark side".

Thanks for the headsup on the transcoding. I an indeed using my desktop as a media server, which would then become the SBC's job... Maybe I'll look into those mini PCs after all.

Some systems have the CPU power limits editable in the UEFI ("BIOS"). No other tools needed.

What's the power consumption when completely idle?

Make sure C-states are enabled, so the CPU cores can switch to low-power modes.

Run powertop and check that the cores are actually entering low-power modes (although, powertop is an Intel tool, so I'm not sure how well it works for AMD).

Thanks for the recommendations! I'll have to check the idle power next time I reboot, since the desktop serves a butload of things (I2P, Tor, Snowflake, my media, seeding...).

I'll definitely make sure about the C-states! :)

Assuming you dont have a platinum PSU, you could upgrade to a more efficient PSU. That probably won't give you as much gains as tweaking bios settings though.

I don't think you can run the PSU but not the other devices attached. Once it powers on, it applies power to the motherboard and it POSTs, starting the CPU and GPU and everything. If you put the PC to sleep, it'll shut off the PSU.

You might also be able to attach a bunch of nvme/sata m.2 drives to an SBC. I've never investigated it. At worst, you could do it over USB, which isn't reliable but you're not holding critical data.

PSU can indeed make a pretty big difference.

If you only have a 80 Plus certified PSU, and see 65 watts drawn at the wall, your system might actually only be using 52 watts, the remaining 13 watts are wasted as heat in your PSU. 80 Plus Gold, Platinum, or Titanium all carry higher efficiencies, but also cost more to buy.

Actual efficiency is also heavily influenced by the load. Most PSUs are most efficient at 50% load. Both lower and higher loads with result in worse efficiency.

Here's an article with some more details: https://www.technewstoday.com/power-supply-efficiency/

I had no idea. Thank you very much for explaining! It'll be "hard" to say goodbye to my trusted ASUS ROG Strix 1000W, which is only an 80+ gold rated old boy... XD

I've seeded on a router from 2013 with 128 mb ram. Transmission client runs on openwrt. It was running all the time as an access point anyways I think using around 4 watts of power. 128 mb of ram was cutting it rather close and I had to add a swap file but the system was running stable.
If you have an old router compatible with openwrt and an USB port to add an external hdd you can build yourself a very cheap and power efficient seedbox.I think the xiaomi mir3g has the same chipset at double the ram.
Those can be bought for around 15-20 Euros used in my region.

Ive been sitting on some Orange Pi RiscV and ARM boards I'm hoping to turn into an arr stack soon here. My first task is to build a raidz1 from an existing mirror with about 2 of 8TB capacity, so it will take a minute.

Im going to be setting up Open Media Vault on an OrangePi RV2, which has 2 m.2 ports, one I have as cache and the other with a 9 sata adapter I'm yet to trial. Ideally this will be able to run off a larger lead acid battery and solar system for an extended period of time, just as a gimick.

I would consider the cost of electricity against the cost of the new PSU.

Did you use a guide / tutorial for undervolting the CPU? I have a similar setup to yours and I'd like to undervolt it soon

I don't have any single guide to recommend, but I do recommend searching for the name of your CPU + undervolting + reddit. Some great threads there!

What I did pick up from my research, is fiddling with the Precision Boost Overdrive in your BIOS, specifically the Curve Optimizer, setting "all cores" to whatever negative value you can push it to = you computer boots without rebooting.

Oh, and if you do heavy work, as in gaming, editing audio and/or video, do some benchmarking before settling on a value.

Sounds good, I'll keep this in mind when I get to doing it on a weekend. My setup's performance needs are low at the moment, but the CPU's a bit exotic (Ryzen 7 Pro 5755G), which is why I didn't dare to delve into the topic of undervolting. Thanks for the advice!

"A little exotic"? I've never heard of that CPU in my LIFE xD hahaha

Fair enough :D I needed an AM4 CPU with integrated graphics and ECC support, so I got this one

Depending on the storage size and electricity use (and vpn), it could be worth switching to a seedbox provider.

Thanks! But I want to be in physical possession of my data. And my VPN doesn't have port forwarding.

You'd still be. But the data would essentially be duplicated.
But since you are asking about power reduction I assume your server is probably not used 24/7 because else you wouldnt really need to reduce the consumption.