Why do people care so much about power usage of the CPU in desktop systems?

It's usually places / people reviewing or promoting Intel CPUs, a common argument to get people to spend more on an Intel one rather than buy a better value AMD CPU.

It's the _only_ real technically accurate advantage of an Intel CPU over an AMD CPU for virtually any cost-based PC build, hence frequently repeated.

I'd rather just have a better-faster-cheaper system.

A really good high-efficiency PSU compared to a cheap one has far more overall effect on the power consumption of the complete computer.
eg. Just 10% lower efficiency on a 600W PSU means an extra 60W used and wasted in the PSU itself.


One of the common leverages used on magazine and online reviewers is basically "You get free stuff as long as you never give [that manufacturer] a bad review.
Reviewers tend to want more expensive stuff to use or sell...


The Passmark site tends to give honest results when comparing CPU power and performance - but even on there, an occasional page gets "lost" (or buried at least) - is it coincidence it's the one that does not have Intel at the very top?
https://www.cpubenchmark.net/multi_cpu_pt7.html

I have two reasons, actually.

1) That power has to come from somewhere. Depending on how long you usually run your computer, the money you pay for that power may be substantial, and in any case, using more power for the same task is a waste of precious resources.

2) That power has to go somewhere. If the CPU uses more power, that means it will generate more heat, which you will have to get out of the case somehow. Depending on the setup of the computer, this will be more expensive, more noisy or "only" hotter for the room or the rack.

Since people often leave computers on all the time it can easily make a difference in your electric bill, particularly with a business that has 100's of computers to consider.
On the opposite end of the spectrum such as with gaming PC's some people seek processors capable of using more power since that can mean faster speeds. An ultra low power processor often means it's handicapped in some way despite the clock speed.

maybe the psu size was near the power draw limit?

Fifteen years ago, a 250W PSU was enough for the most demanding power users then. Today, GPU's alone would falter on anything less than 500W.

You can save a lot a money a year depending on how hard you work your CPU.
You can get cheaper, quieter cooling systems with lower power CPUs.
You can get cheaper PSUs.

Do you not pay your power bill or something? A typical gaming computer that's always on can easily cost $300 a year to run. Surely you'd know this if you've been building computers for 15 years...

Maybe there was a decision to make about whether to upgrade the power supply. Or maybe it was just a matter of trying to save power usage for bandwidth or cost reasons. If there's a decision to make, and cost, performance, and usage, etc. are all the same and the only difference is the efficiency of the component, I think most people would go with the more efficient one.