Super high efficiency 300-400W PSU?

Notice: Page may contain affiliate links for which we may earn a small commission through services like Amazon Affiliates or Skimlinks.
G

Goof

New Member
Jan 27, 2021
10
5
3
What exists for super high efficiency, lower wattage power supplies? Ideally in the 300-400W range, if not 275W. Both SFX and ATX form factors are fine.

I'm trying to avoid any rackmount-oriented PSU in particular unless they are provably silent (or silent at 2m) at 150W -- likely 100-120W -- or lower load. For example, total system idle may be as low as 40W. Cost not really a factor, but ideally it shouldn't be bananas (like 2x or 3x price) for TCO reasons.

For connectivity I need the usual ATX 20+4, CPU 4-pin, and four Molex connectors for a storage backplane. Modular heavily preferred, but not required.

-- -----

80 Plus Platinum power supplies are rare in lower wattages, and I've yet to find a Titanium one. Corsair has the SF450, but with 115V I may only hit 91.5% efficiency under my expected load (150W or less is expected peak), and only 87% efficiency at idle (probably 40-45W).

Seasonic has the Focus PX-550, but since the expected load is so low, efficiency is considerably worse compared to the Corsair SF450.

-- -----

I appreciate what you all can come up with!
 
B

BlueFox

Legendary Member Spam Hunter Extraordinaire
Oct 26, 2015
2,554
2,014
113
They're not common at low wattages like that because there's little demand and the higher efficiency makes a negligible difference. You're looking at a couple watts at idle and under 5W under load. In the scenario where your system runs 24/7, say half under load and half idle, I would estimate ~$3 annually in extra cost for 80+ Platinum vs 80+ Titanium. In most cases, the added cost would be greater than the energy savings over the lifetime of the power supply.

With that said, if you only need that little, why not just go for a 12V external power supply? They're lower wattage and you could forego any fans.
 
G

Goof

New Member
Jan 27, 2021
10
5
3
>"They're not common at low wattages like that because there's little demand and the higher efficiency makes a negligible difference."

Trust me, I've noticed this. :) 550-650W seems to be the real floor for Titanium now, and 450W seems to be the floor for Platinum with what's actually available. I'm aware I can go look at the 80Plus certification list, but for lower wattages you're looking at stuff that was certified closer to a decade ago and hasn't been available for eons.

My power consumption cost is a bit higher. Near Boston my yearly average is $0.266/kWh, and more like $0.286/kWh in winter. Yes, it's peanuts in the scheme of things ($2.33 per Watt per year), but there's other reasons I'm trying to drive the number down (mostly a challenge for myself). For someone in Germany though, things might matter even more (I think $0.55/kWh)! I'm curious how much a difference the future switch to ATX12VO will bring.

12V external certainly an option, but certainly looking for something more turnkey. Being able to just find the Corsair SF450 (best I've seen with measurements, including third-parties) so far, plunk down $85, and plug it in is hard to beat by comparison.

Believe it or not the project is a storage server that genuinely performs. Multi-volume, 72.5TiB usable (eight drives, plus dual NVMe for ingest/caching tier), capable of saturating 40GbE connectivity (yes!), with an anticipated idle (at 85% efficiency) of only around 40W, and peak load may be still sub-110W at the wall, and certainly sub-125W.
 
Last edited:
  • Like
Reactions: abq
Tom5051

Tom5051

Active Member
Jan 18, 2017
359
81
28
48
Usually you can find the graph on the PSU manufacturer's website that will tell you how efficient the unit is depending on the load.
Find one that is most efficient around the power you expect to use.
 
  • Like
Reactions: ptf
R

Rand__

Well-Known Member
Mar 6, 2014
6,713
1,819
113
BlueFox said:
They're not common at low wattages like that because there's little demand and the higher efficiency makes a negligible difference. You're looking at a couple watts at idle and under 5W under load. In the scenario where your system runs 24/7, say half under load and half idle, I would estimate ~$3 annually in extra cost for 80+ Platinum vs 80+ Titanium. In most cases, the added cost would be greater than the energy savings over the lifetime of the power supply.
Click to expand...
Half load is the most efficient are for a PSU though, more interesting are the edges... If you look at the 40-100W range then the differences are larger (->10% load). O/c its not so simple as its all relative to the specified max power and usually you get Titanium only at higher Wattages, but depending on the actual price difference it *can* make sense if you avoid the unregulated areas...

That said, for my low power 19" build I tend to use the Supermicro 340W 1U Multi-Output Power Supply (PWS-341P-1H) (if i can get it cheaply). Its not silent so does not fit the OPs requirements but it was the basically the lowest power platinum PSU i found (when i was looking a couple years back)


BlueFox said:
With that said, if you only need that little, why not just go for a 12V external power supply? They're lower wattage and you could forego any fans.
Click to expand...
How do you connect these to a regular board? I have a board with 12V power in i think but wouldnt know how to convert the round plug that comes with these 12V PSUs to the 4 pin input on the board.

Another option are picoPSUs ... I played around with one a few years back too, but ultimately didnt deploy it since it was flaky on the intended box (prolly due to the Tapedrive drawing too much power after all).
 
  • Like
Reactions: abq and Jona
B

BlueFox

Legendary Member Spam Hunter Extraordinaire
Oct 26, 2015
2,554
2,014
113
Rand__ said:
How do you connect these to a regular board? I have a board with 12V power in i think but wouldnt know how to convert the round plug that comes with these 12V PSUs to the 4 pin input on the board.

Another option are picoPSUs ... I played around with one a few years back too, but ultimately didnt deploy it since it was flaky on the intended box (prolly due to the Tapedrive drawing too much power after all).
Click to expand...
Like you said, simple adapter or the likes of a PicoPSU. Many newer Supermicro ITX motherboards don't even have ATX plugs anymore.
 
Bjorn Smith

Bjorn Smith

Well-Known Member
Sep 3, 2019
906
504
93
52
r00t.dk
I have my firewall running off a pico PSU - the only disadvantage to that is that you are stuck with an external power brick - which is silent but probably not very efficient :)
 
G

Goof

New Member
Jan 27, 2021
10
5
3
Looks like this exists as of next month. No efficiency curves yet, but I'll be reaching out. Historically they've made adapter plates.

hdplex.com

HDPLEX 250W GaN Passive AIO ATX Power Supply

Free Shipping Worldwide Stock Status USA : In stock Germany : Sold OutASIA : In StockUK : Sold Out Australia : In Stock
hdplex.com hdplex.com

250W. Supposed 94% peak efficiency. Entirely passively cooled. My question is how high the efficiency will be at very low loads (50W or less).
 
  • Like
Reactions: abq
Stephan

Stephan

Well-Known Member
Apr 21, 2017
1,128
895
113
Germany
Bought three Seasonic Prime Titanium Fanless 600W ATX 2.4 (SSR-600TL) recently, won't get much more efficient at 40-50 watts. About 92% at 10% load. No sound at all. Super low ripple and stable voltage regulation. Long warranty. But expensive.
 
C

crlt

Active Member
Jul 12, 2024
85
106
33
I cant imagine much has changed since but has anyone found some quality units in this range? I'm planning to build six quiet short depth 2U nodes and the main obstacle is finding an efficient ATX/SFX PSU.

The Corsair SF450 and Seasonic PX-450 seem to no longer be available. Super Flower has a few units but dont seem to be sold in the US market.

Was considering the Seasonic Focus Gold 550W with the Hybrid Fan feature but seems those are no longer sold either.

I've seen mention of GAN units but theyre not cheap and Im not sure about running them 24/7 in my home env.
 
T

twin_savage

Active Member
Jan 26, 2018
171
128
43
36
Goof said:
Looks like this exists as of next month. No efficiency curves yet, but I'll be reaching out. Historically they've made adapter plates.

hdplex.com

HDPLEX 250W GaN Passive AIO ATX Power Supply

Free Shipping Worldwide Stock Status USA : In stock Germany : Sold OutASIA : In StockUK : Sold Out Australia : In Stock
hdplex.com hdplex.com
Click to expand...
I'm running the 500w version of this PSU in my Jonsbo N3 and I have no complaints. It's got a little fan in it but I never hear it turn on.

crlt said:
I've seen mention of GAN units but theyre not cheap and Im not sure about running them 24/7 in my home env.
Click to expand...
Most of the time when a manufacturer mentions GaN, it is purely a marketing term and doesn't have an impact on actual performance since they'll use some token GaN FET on a PFC boost circuit instead of something important like the actual buck converter inside the PSU.

Also GaN FETs aren't necessarily better than Silicon MOSFETs; they (GaN) typically have lower switching losses but also have higher RDS_on values which makes them more suitable for really high switching frequencies which aren't usually in computer power supplies unless you want to miniturize them by making the transformers and inductors in them really small.
 
  • Like
Reactions: abq and crlt
C

crlt

Active Member
Jul 12, 2024
85
106
33
Thanks for the info gents, with all that said the hdplex is imo overpriced for what it is when factoring in 6x nodes. And the sf450 is unattainable in the US market currently
 
T

twin_savage

Active Member
Jan 26, 2018
171
128
43
36
louie1961 said:
The Corsair SF450 Platinum will be ~ 90% efficient at 100-120 watts. BUT you will need adapters to get to 4 MOLEX connectors
Click to expand...
Be extra careful with the SF450. The majority of "SF450"'s produced are not the model that Cybenetics reviewed (RPS0111) and perform noticeably worse.
The easiest way to filter out all these inferior SF450s (RPS0025 and RPS0072) is by the badge, the "good" version will have a solid looking badge and the inferior ones will have little lines in front that break of the silhouette of the badge like in the newegg link shared.
 
  • Like
Reactions: crlt
K

kapone

Well-Known Member
May 23, 2015
2,064
1,397
113
If you can shoehorn an HP common slot (1U) PSU and the associated PDB into your case…pros:

- cheap
- built like a tank
- platinum rated and the 460w version is just about perfect for anything, other than a storage server, although even that…
- literally silent. From more than a foot away, you’ll not hear it.

I use a boatload of these and I haven’t had a single one fail in >10yrs.
 
  • Like
Reactions: crlt
C

crlt

Active Member
Jul 12, 2024
85
106
33
kapone said:
If you can shoehorn an HP common slot (1U) PSU and the associated PDB into your case…pros:

- cheap
- built like a tank
- platinum rated and the 460w version is just about perfect for anything, other than a storage server, although even that…
- literally silent. From more than a foot away, you’ll not hear it.

I use a boatload of these and I haven’t had a single one fail in >10yrs.
Click to expand...
Those really are dirt cheap... <$15 on the bay and server grade. I didnt realize they had such a unit. Havent bought the rack mounted cases yet so it makes sense I try to find a not too long case that fits this and the PDB. Thanks!!
 
K

kapone

Well-Known Member
May 23, 2015
2,064
1,397
113
They’ll need minor surgery (on the PDU), if using a non HP motherboard, but it’s trivial. Shorting two wires.
 
  • Like
Reactions: crlt
You must log in or register to reply here.
Top Bottom