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Comment by gnufied | Hacker News Reader

> The switch to 5 nm gives "Zen 4" 62 percent lower power for the same performance,

I know this is a desktop launch and all but I wonder how much does this update catches upto Apple M1/M2s. With 6000U series CPUs the gap was already closer - https://www.youtube.com/watch?v=YOSQIUGGdYE but it looks like this will get it pretty close. Obviously getting Laptops on new 7000 series will take time. AMD's achilles heel has always been availability when it comes to Laptops.Many paper launched SKUs of 6000 series Laptops are still not available in US market. Heck, you will be hard pressed to find a 99W laptop with AMD only CPU (basically Apple's flagship 16inch configuration).

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> I wonder how much does this update catches upto Apple M1/M2s.

>The greatest performance gains are actually at the lowest TDPs, where the 7950X saw a 74% increase in Cinebench R23 MT performance. These advantages actually decreased as TDPs went up, dropping to 37% at 105W, and finally 35% at 170W.

When AMD isn’t loading CPU clockspeeds into the stratosphere – which is always well into the diminishing returns of the voltage/frequency curve – Zen 4 is significantly more power efficient than its predecessor.

https://www.anandtech.com/show/17552/amd-details-ryzen-7000-...

The problem is that Intel is reviving their Pentium 4 strategy of performance via ridiculous frequencies and voltages, and AMD is following suit.

Contrast to Apple, where the strategy is throwing die space at more execution units and running the clocks at the efficient end of the voltage frequency curve.

The M2 clocks up to 3.5 Ghz, while AMD is targeting up to 5.7 Ghz.

> The problem is that Intel is reviving their Pentium 4 strategy of performance via ridiculous frequencies and voltages, and AMD is following suit.

> Contrast to Apple, where the strategy is throwing die space at more execution units and running the clocks at the efficient end of the voltage frequency curve.

That's the benefit of having a single customer. Apple knows they're never going to build mobile devices with good thermals, so their chips will never clock to the moon, so they have freedom to make a much wider core that (almost certainly) has larger clock domains and would be difficult to run at higher clocks.

Otoh, AMD has many customers and those customers like high clockspeed, and their competitor will give it to them, so AMD needs to have a design that can clock to the moon, but also be power efficient at lower clocks.

> Apple knows they're never going to build mobile devices with good thermals

They seem to be doing just fine with thermals.

>Like the 2020 M1 MacBook Pro, this laptop doesn’t get overly warm. Its underside reached a maximum temperature of 85 degrees, which is ten degrees lower than what we consider to be uncomfortably hot for a laptop. Likewise, the touchpad never went above 79 degrees.

This is one of, if not, the coolest-running and quietest laptops I’ve ever used.

https://www.tomsguide.com/reviews/macbook-pro-13-inch-m2-202...

Contrast to the Dell XPS 13 Plus:

>the XPS 13 Plus' fan was really struggling here because, boy oh boy, did this thing get hot. After a few hours of regular use (which, in my case, is a dozen or so Chrome tabs with Slack running over top), this laptop was boiling. I was getting uncomfortable keeping my hands on the palm rests and typing on the keyboard. Putting it on my lap was off the table.

https://www.theverge.com/23284276/dell-xps-13-plus-intel-202...

For those who want a laptop, chasing performance via ever increasing clock speeds and voltages is problematic.

The point is that they are doing well with the limited thermal stress their CPUs put off, very intentionally.

> The greatest performance gains are actually at the lowest TDPs, where the 7950X saw a 74% increase in Cinebench R23 MT performance. These advantages actually decreased as TDPs went up, dropping to 37% at 105W, and finally 35% at 170W.

My money is on the new I/O die being the source of most of the improvement in the low TDP range. That thing was pretty power hungry on 12nm GloFo; 6nm TSMC is a pretty sizeable leap.

Obviously there are improvements everywhere in the V/F curve, implying that the CCDs have also had solid improvements, but since I/O die power draw doesn't change much with CCD frequency, it's a bigger slice of the pie (so to speak) at lower clocks.

Apple's family of chips by large focuses on performance per watt because it's a primarily mobile chip - made for laptops. The Mac Mini/Studio is more of a side effect than primary target.

If they will have something special for Mac Pro, it would resemble AMD's strategy.

> AMD is following suit

I don't think it's a "problem" per se.

TDP is a ceiling, "power consumption under the maximum theoretical load", and it allows for higher clocks, yes, and especially across more cores.

Unlike Apple, AMD and Intel have to compete with each other and care about how well games perform. So single core clock speed matters more. So while they work towards efficiency on the one end, they still try to push upwards on thermal headroom and clock speeds.

It would be a problem if Intel and AMD only chased high clock speeds, but ignored everything else (especially efficiency) entirely. But Zen 4 is a terrible example of AMD ignoring efficiency. (+13% IPC, +74% performance at 65W compared to Zen 3.)

The M2 is on Low Power Node, AMD is on High Frequency Node along with IOD.

So in theory AMD Zen 4 APU on the same Low Power N5 should be even more efficient.

But if we do Geekbench 5 with linear scaling, my guess would be the Zen 4 still only gets about 1400 point with 3.5Ghz in the best case scenario. Which is still not bad.

A lot of what Apple has shown to the world with A13 to A15's design will be coming to Zen 5 and its iteration Zen 6. I suspect only then will we see AMD catching up.

Or Nuvia / Qualcomm and Apple still has a few tricks to further increase Pref / Watt.

For Zen 4 a good part of the power reduction is that the i/o die went from the Global Foundries 12nm process to TSMC's 6nm process. That probably accounts at least partly for the large drop in power for the same performance, making it unlikely that Apple will see the same drop.

Where does the article say "The switch to 5 nm gives "Zen 4" 62 percent lower power for the same performance,"?

Was the article linked changed?

Details covered in the AMD presentation can be found at Anandtech's article.

https://www.anandtech.com/show/17552/amd-details-ryzen-7000-...

There, you'll see "up to 62% lower power for the same performance" and "up to 49% more performance at the same power."

Yeah the M1/M2 chips are amazing. In this one test the 5950X is about 50% slower than the M1Max so perhaps the 7950X will close the gap even more: https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=1498...

Encoding is usually done by hardware accelerators (located on the GPU) and is generally unrelated to the performance of a processor. Additionally in the video they're comparing hardware accelerated video encoding to software encoding; it's honestly surprising it's only half as fast. Here's a comparison showing the rtx3090 ahead of the Mac Studio in encoding: https://youtu.be/f-mbtSRz2nk?t=550

Sure but the 3090 is going to use a ton more power and release a lot more heat than say a M1Max studio.

Then again, at the same time, the 3090 machine can do CUDA and other useful things.

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