I am trying to choose a proper PSU, but it’s hard to find a high-efficiency, low-wattage one. The “best” I have found so far is the be quiet! Straight Power 11 Platinum at 550W, but that’s 180€, which is absurd to me because I paid as much for my 1000W 80+ Gold Corsair PSU in my desktop PC. Am I missing something? I’d be glad to hear any tips on choosing a good PSU from more experienced builders.
There are no real size constraints for me, it just has to be “ATX ≤170–240 mm” according to the case specs, so probably best below 170 mm but stretching to 240 mm if needed. Pretty sure that’s about all of the consumer ones.
Budget is a mixed bag, I’d invest more upfront if it’s platinum or higher considering power prices here are insane, but overall I’d like to keep it below 125€ if that’s somehow possible, with a stretch to 150€.
According to a PSU calculator I’ll probably need at most 350W, unless I decide to put a GPU into my NAS.
This contradicts any research I have done so far…
From the threads I’ve found on Reddit, the LTT Forums, and the Level1Techs forums, even a NASCompares video I’ve watched, everyone was saying that one should at the very least go for Gold and if possible Platinum or higher.
I do see the difference, it is just a couple percent apparently, but then I’m wondering why so many people go on about high efficiency ratings.
I think it may be easier & cheaper to find a gold 650w or 750w. I’d rather over than under provision psu, even for a nas. You never know when you’ll find a new stupid usecase & plug in a gpu.
It is certainly easier and a slight bit cheaper, however from what I am aware PSUs are most efficient near 50%, right? So I am inclined towards getting it somewhat right.
I see your point though, however sadly you also completely contradict what truenas-fan said above with
I’m probably a lone voice, but in my opinion there is no need to “overwatting” the PSU on a machine that will idle 99% of time above 50~60w of power consume, and probably power on just few times every month. Indeed, can kill the efficency because the PSU itself will not run in his optimal range.
Also to consider, despite the tier assigned, PSU can works better on certain range and worst on other.
But IMHO the choice from a gold or a plat Is easy: just pick the cost difference from the gold one and the plat, calc the gain from the better efficency of the plat, apply It to you electricity cost and see after how much time you will start save money on bills. If you start gain something after warranty period expire, most probably its not worth, otherwise think that extra money spent now are an investment
I doubt you will find many 80+ Platinum at low wattages: It just doesn’t make economical sense.
That’s their operating sweet spot, but the 80+ ratings are defined looking at top load… and also at lower loads for the higher grades. So, for the same maximal power, Platinum would get you a few % better than Gold, but the extra PSU cost will vastly exceed the operational savings.
And if you go to Platinum 650+ W rather than 450 W Gold, your idle NAS will operate at an even lower % of the maximal load of the PSU… meaning that it is not even certain that Platinum@7% would fare better than Gold@10%.
So I second @truenas-fan here: Check your calculations, add a fair safety margin, and then get a 80+Gold from Seasonic (why settle for less?) at that level—but do not oversize by 200% or 300%.
The most important thing is to know your idle load (or the load where you’ll spend most of your time). If that is lets say 60W then you need to match that with peak (or good efficiency).
Most PSUs begin to be efficient only at 10 (or even 20%) nominal load, so a 600W PSU might be ok if you’re at 60W+ (as you reach the 90+% efficiency target).
eg Pure Power 13 M Gold 550/600W
80 Plus Zertifizierung
Gold
Effizienz (%) bei 230V, 2% Last
70.3
Effizienz (%) bei 230V, 10% Last
90.1
Effizienz (%) bei 230V, 20% Last
92.8
Effizienz (%) bei 230V, 50% Last
93.8
Effizienz (%) bei 230V, 100% Last
92.1
Now if you’re looking at money only then paying a premium of €100 to go from 90% to 92% or 94% is not sensible, as you can run it years before it regains that extra initial cost, but o/c using less power is desirable for other reasons too (nature, heat etc)
