Notice at 185W, the Ryzen 9 7950X is churning out about 36% higher performance than the Core i9 13900K. The Intel CPU, however, is then able to continue drawing up to 335W!

At their respective peak scores, the i9 is using over 70% more power.

[0] https://www.techspot.com/review/2552-intel-core-i9-13900k/

[1] https://static.techspot.com/articles-info/2552/bench/Power_S...

I use high performance only for seconds when compiling.

From https://www.tweaktown.com/reviews/10195/amd-ryzen-5-7600x-ze...

"Power consumption is measured directly from the dual eight-pin connections. At peak, the 7600X pulls an impressive 130W, and during idle, it was down to 18w."

Sounds pretty good, especially considering its at the "dual eight-pin" power supply connection. Not laptop class, but pretty good for a high performance desktop.

AMD is killing it with efficiency there.

Apparently Intel's trying really hard on an old process to get the performance crown, forcing AMD to clock higher than they'd like to compete. It's ridiculous that they double the power for 10% performance. But the nice thing is you can half the power and take the 10% hit.

Also note that the 7900/7900X are dual chiplet design that has a significant power impact. The 7700x and below have a single chiplet and saves power, and also increases single thread perf. If you look at the gaming benchmarks the 7700x is often better than the 7900x, not to mention all the Intel chips except the top of the line i9.

So if you buy the 7700x and underclock just a bit you should have a very efficient desktop.

This is a minor terminology mix-up. The term you want here is "CCX". Each CCX holds multiple chiplets.

See https://www.tomshardware.com/reviews/amd-ccx-definition-cpu-... for more details.

EDIT: It does look like my own information on this was rusty.

A "chiplet" is not an individual core, but a trimmed down die that does not have a memory controller. A "CCX" contains cores (within a chiplet) and L3 cache.

https://www.hardwaretimes.com/amd-ccd-and-ccx-in-ryzen-proce...

> The basic unit of a Ryzen processor is a CCX or Core Complex, a quad-core/octa-core CPU chiplet with a shared L3 cache.

From that link, your statement does not appear accurate. Multiple CCX's appear on a given Core Chiplet Die. There are indeed two vs one core chiplets on different Ryzen designs (plus the IOD).

The popular tech press understanding of how closed-loop control systems work is just REALLY annoying.

So I am actually surprised at how well AMD Zen 4 is doing. It used to be if you want MT you go with AMD, at the expense of ST. Now this is no longer the case.

If you care about energy efficiency, just buy AMD Zen 4.

Not sure if it gets closer to the testing approach you're looking for?

Both 7950X and 13900k don't lose much performance from limiting power to "reasonable" wattage.

My work PC with a 4th gen i5 has been unusable even for basic tasks for a few years, despite the 16 GB of RAM and SSD drive. Even moving windows around and stuff is sluggish.

Yes and no. AMD just released the 5800X3D which is just a teensy bit slower than Intel's top-dog...but it uses a bit more than one third the power the I9-12900KS and 13900K do.

Right now you can get a blisteringly-fast (for gaming and other certain specific workloads) AMD CPU with power consumption a skooch over 100W. It yields a nearly 25% increase in framerate on some games, which is huge, and does it at less power usage than the non-stacked-cache variant: https://youtu.be/hBFNoKUHjcg?t=515

You're right about the next generation of Ryzen processors using more power, but nobody knows how much, partly because AMD using some silly nonsense to calculate "TDP", and review units aren't out yet: https://youtu.be/hVnJbiYOCq4?t=363

In 1080p gaming (useful for exaggerating the CPU bottleneck), the 13900K outperforms the 5800X3D by about 11%[1].

Review units of "next generation of Ryzen processors" have been out since late September when they became available to buy, so you can read reviews and find out their actual power usage[2]. The Ryzen 9 7950X is shown to push system power consumption up to 355W while running Blender.

(TechSpot reviews linked simply because they include power consumption in their reviews.)

[0] https://www.techspot.com/review/2449-amd-ryzen-5800x3D/

[1] https://www.techspot.com/review/2552-intel-core-i9-13900k/

[2] https://www.techspot.com/review/2535-amd-ryzen-7950x/

At idle, where the cpu spends most of it's time, the Intel chips are winning significantly.

Well, by 3W for an entire system. Which isn't worth worrying about in my opinion.

So personally, I'd be looking at other specs to help me decide between them.

https://www.guru3d.com/articles_pages/intel_core_i9_13900k_r...

For day to day use (including non-gaming work) my old Intel CPU consumes less power overall because the idle power was so much lower.

Peak TDP isn’t everything.

How often do you run your CPU at 100% load across all cores? For me, idle power draw dominates my overall power consumption. The difference between a 100W peak CPU and a 300W peak CPU basically doesn’t matter across the course of my day, because even compiling large codebases doesn’t last very long.

I say this because I bought into the AMD efficiency hype a few years ago, ditching my Intel workstation for an AMD workstation. Yet according to my home energy monitor, my office circuit consumption actually went up, not down.

Further investigation revealed that my AMD desktop had significantly higher idle power than the old Intel one. Given that most of my day is spent typing, not pegging the CPU at full load, this nets out to higher overall power consumption.

So I’m back to not caring about peak power consumption. If the Intel CPU wants to pull 300W for the 60 seconds that my compile takes, go for it. What I’ll really be looking at is the idle power usage.

For my desktop, I only care if it's possible to make it quiet overall.

For a laptop, I care about performance given the more restrictive cooling restraints of the form factor, and battery life (but that's secondary since I can usually use it plugged in anyway.)

So efficiency matters (including under load), but it can't be your only deciding factor in deciding what to buy and use.

And then having a processor drawing this kind of power has impact on you PDU, cooling system, case...

mATX for instance makes nearly no sense with that kind of power use. But who wants a huge tower on their desk anymore?

It seems to me like people only care about peak power consumption when AMD and Apple win those benchmarks.