Power consumption: desktop vs "mini pc"

[tmcrnll]

I'm looking for some hardware to build a small nas, (with nextcloud and plex) and a minecraft server, and I was wondering: if you get for example a dell elitedesk or prodesk, one of the really small ones, how does the power consumption compare to a full sized desktop of the same specs?
I did an offer of €140 for an HP prodesk with an i5-8500, 16GB memory and a 256 Gig ssd. Is that a good deal? (the offer was accepted)

 

[CyklonDX]

I've got HP EliteDesk 800 G2 Micro (i5-6500T 8GB RAM 120G SSD) i use it for playing videos from my media server.
Playing HDR video in browser on linux (suse) on 4k tv its capable of eating ~100W in peaks.
Its idling around 15-30W.

vs

While a custom desktop (same setup, same use as the micro)
3900x (locked max clock 1.6GHz)
1x8GB 2133MHz RAM
radeon 5700
750W Platinum
2x3k rpm noctua fans.

on stock/balanced performance mode eats around ~280W while playing 4k hdr content in browser.
on full power saving mode with p states in bios ~120W, clock lock to 1.6GHz (didn't test disabling cores..., and forcing p states on gpu) while playing 4k hdr content in browser, and idling around 35-45W

-- potentially wattage could be much lower if was using apu/lower end newer gpu, and newer zen/intel arch with lower core count, as they are far more efficient at lower clocks. (a single fan / passive or lower rpm fan settings could also reduce some wattage)

//

In terms of euro, its hard for me to say; in US 2years ago i bought that hp elitedesk for $100; power was not my consideration point for swapping to hp micro - only size.

 

[i386]

I think that a desktop tower will be slightly better for power consumption due to cooling.
Larger volume, larger but slower fan(s) in the desktop vs small volume, small but faster (and always running?*) fan in limited space

* I don't have any experience with these small systems and I know there are completely passively cooled systems

 

[tmcrnll]

Could you see a desktop running at 10-15 watts, though? I wouldn't think so, but that's what a lot of those mini PCs run at while idle.

 

[tmcrnll]

And wouldn't the difference in components be more significant? I'd think that a desktop psu, motherboard and ram would be more powerful (as in Watts)

 

[i386]

Could you see a desktop running at 10-15 watts, though? I wouldn't think so, but that's what a lot of those mini PCs run at while idle.

For me idling means the system is running, no user is logged in/desktop not loaded and no services/application running. If it's doing "nothing" then even 15 watt would be too much.

And wouldn't the difference in components be more significant? I'd think that a desktop psu, motherboard and ram would be more powerful (as in Watts)

From you question in the op I assumed you mean same/similar (in terms of power consumption) components.
Comparing a 1000watt desktop with a tiny miny micro system powered by a 45watt power brick is of course something different...

how does the power consumption compare to a full sized desktop of the same specs?

 

[tmcrnll]

For me idling means the system is running, no user is logged in/desktop not loaded and no services/application running. If it's doing "nothing" then even 15 watt would be too much.

Idk, on other forums I've seen people saying that their idle system uses between 5 and 15 watts. I mean with applications running, but not actually doing a lot.

From you question in the op I assumed you mean same/similar (in terms of power consumption) components.
Comparing a 1000watt desktop with a tiny miny micro system powered by a 45watt power brick is of course something different...

I meant similar in terms of performance. So comparing a tiny mini micro system to a desktop with similar performance, for example a mini pc with a 8500T and a desktop with an 8500, as I said.

 

[CyklonDX]

by default obviously micro/mini pc is going to win... Just because of clocks being so different.

Only after you put some work on desktop by limiting clocks, disabling cores etc to match your 'low power' part is where things become blurred as desktop parts often will outperform its LP equliviant, at lower wattage than low power parts used in micro pc's. It also comes to silicon quality at that point, and undervolting; as well as what parts there are in your desktop/server build. Micro/mini pc's often do not have great parts, and wouldn't even clock when overclocked to normal desktop part clocks - as they are often poorer silicon quality too.

 

[tmcrnll]

Aren't the lower power chips just limiting the maximum wattage? That wouldn't make a difference then when idle, right? That's what I'm concerned about, as most of the time it's gonna be doing nothing.

 

[CyklonDX]

Well it comes how intel calculates TDP... and that's a mess.

i5-8500 when downclocked should eat same wattage the 8500T does...
Potentially i5-8500 will eat less wattage, as 8500T is likely made from worse silicon (ASIC quality)

In linux you can lock turbo to specific downclocked state (like 1.6GHz it has on 8500T, where it will eat '25W', and i don't know how low it can get, you would have to check - 3900x from ryzen could go as far as 800MHz; if you turn off cores - have that option in bios you can save even more power there)

 

[cheezehead]

While a lower draw is always better, also factor in UPS runtime and local power costs. Around here, I can save a sizable chunk on slightly less efficient hardware but it only costs a few dollars/year in electric with a power saving ROI vs electric spent of 5+yrs.

 

[Samir]

It's pretty easy to see the power differences if you look at the power supplies. It doesn't help with the minimum power, but something that has a 300w power supply is definitely different than something that maxes at 65w.

I see people talk about power on homelabsales all the time as if a newer server is somehow going to automatically use less power--and yet newer servers come with a lot higher wattage power supplies than previous generations. Yes, they can be more efficient, but unless you need all that performance, perhaps moving off a server is the best power savings...(which ironically is what a lot of people end up doing once they figure out what they're doing).