Forgetting about efficiency curves

[r00tb33r]

I noticed a recurring trend on here.  People with frankly modest rigs with huge power supply wattages.  And then there's the group that preaches getting them.

 

Fact is, efficiency is low at a low load.  There's no point in getting these 750, 850, 1000w power supplies if you have a pedestrian machine.

[seon123]

Have you ever looked at the efficiency of a PSU? mUh EfFiCiEnCy CuRvE is completely exaggerated, and the efficiency is pretty much a horizontal line. Newer PSUs will often meet the requirement of 70% efficiency at just 2% load, go up to ~85-90% right after, and stay at a pretty much constant efficiency up to 100% load. 

 

 

For concrete examples: 

 

CX650M 2021 (entry level):

71% at 20W (3% load)

84% at 65W (10% load)

89% at 260W (40% load, peak efficiency)

83% at 650W (100% load)

 

RM650x 2021 (fairly high end):

80% at 20W (3% load)

87% at 65W (10% load)

91% at 325W (50% load, peak)

87% at 650W (100% load)

 

RM1000x 2021: 

78% at 20W (2% load)

88% at 100W (10% load)

91% at 300W (30% load, peak)

86% at 1000W (100% load)

 

AX1600i (top end): 

69% at 20W (1.25% load)

80% at 40W (2.5% load)

92% at 160W (10% load)

94% at 480W (30% load)

91% at 1600W (100% load)

 

 

All of them were at more than 80% efficient at 40W load, and all of them barely changed their efficiency from 10% - 100% load. 

All numbers from their Cybenetics reports. 

 

43 minutes ago, r00tb33r said:

Fact is

Fact is, you're not doing any basic research, and spreading misinformation. 

 

 

There are valid reasons not to choose an excessive PSU, but efficiency is not one of them

[r00tb33r]

47 minutes ago, seon123 said:

Fact is, you're not doing any basic research, and spreading misinformation. 

 

https://www.anandtech.com/show/2624/debunking-power-supply-myths/3

[seon123]

5 minutes ago, r00tb33r said:

https://www.tomshardware.com/reviews/psu-buying-guide,2916-3.html

Your idea of research is a squiggly hand drawn line that shows a normal PSU being above 80% efficient at 150W load, and stays between 80%-85% efficiency from 150W-650W...?

 

Not that I should be surprised, coming from you ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

[r00tb33r]

33 minutes ago, seon123 said:

Not that I should be surprised, coming from you  ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

Was I supposed to be insulted?

¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

[seon123]

2 minutes ago, r00tb33r said:

Was I supposed to be insulted?

¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

No, that would require you to comprehend something. It was meant others to chuckle at. 

[Lurking]

2 hours ago, r00tb33r said:

 

https://www.anandtech.com/show/2624/debunking-power-supply-myths/3

Technology did not improve since 2008 when that article was written?

 

Yes, extreme oversizing isn't good. But choosing platinum efficiency is a better strategy than worrying about a 50W larger PSU. 

 

If you use the manufacturer sizing tool, or parts picker, and verify here in the forum, you won't end up with an extremely large PSU.