Intel Announces 13th Gen "Raptor Lake" - Linux Benchmarks To Come

[coder]

I'd say TDP is a rough estimate for thermal solution, which guarantees that CPU is going to work at least at base frequency.

That used to be the case, but if PPT is 1.35x of TDP and unlimited in time, then it renders TDP a complete fiction for any purpose.

This situation has gotten so ridiculous that we really need governments to start dictating how these metrics should be quantified, like they do the fuel-efficiency metrics for automobiles. That's the only way to stop this madness.

[arQon]

Anyway my issue is that AMD changed definition of their TDP (what video exactly mentions). Before TDP was actually the power your CPU drew from EPS rail.

... What?! No it wasn't, and it was never that even back in the days when Intel - which is, incidentally, not the same company as AMD - still even pretended it was.

> Intel meanwhile implies 2 things one is base power draw and boost power draw and with exception of some AVX512 workloads you will not break that boost power draw.

Again: ... What?! Intel has been lying about TDP since before you were born.

coder

re TDP in general: it's a fiction. It's always been a fiction, but now it's just absurdly so (in much the same way that lies in, say, politics grow over time, like boiling a frog).

That's it. That's literally all there is to it.

The "rough" TDP is an imaginary thermal output under an imaginary load with an imaginary cooler in an imaginary environment, which once upon a time was based on vaguely-realistic numbers for at most one of those terms.
The "official" TDP is whatever nice round number is vaguely within cannon range of the original fictitious number that Marketing likes, and is slightly lower per perf unit than whatever the competition's is.

That's *before* the creation of boost clocks, let alone the infinite boost clocks that have been around since ?Sandy? ?Ivy?.

AMD's 90W sustained in 65W mode is, I suspect, a bug rather than willfully deceptive **, but Intel has been "off" by staggering amounts at times for years now on multiple chips, so it's possible AMD is just following suit because it has to. Obviously, if one company is misrepresenting its CPUs by well over 50W, and one is "only" doing so by 10W, the latter is going to get creamed on perf/W judgements unless they have a design that's 20%+ more performant at a given power draw. We've seen one of those in the past decade, thanks to 14++++ vs TSMC7 Zen, so it can happen, but it's pretty rare and not something you can bet the company on year after year for a decade or more.

** Simply because at the other power draw targets it's pretty close, but the 65W behavior is an outlier so I'm giving them the benefit of the doubt. I won't be shocked if no AGESA/microcode update fixes it for several months though, or indeed, ever.

As far as "then it renders TDP a complete fiction for any purpose" goes? Yeah, pretty much. I'm not sure exactly when it went from "kinda sorta at least *vaguely* representative of reality" to "not even remotely so" - like I say, it was boiling a frog - but it's been there for a very long time now, and I don't see that ever improving. (Unless forced to by some EU regulation or something, but they've got bigger fish to fry right now, and Intel has deep pockets).

edit> I'm buried in post-vacation backlog right now, so I'm trying to minimize posting, but if you need a couple of examples to understand how the process is perverted let me know.

[drakonas777]

That used to be the case, but if PPT is 1.35x of TDP and unlimited in time, then it renders TDP a complete fiction for any purpose.

This situation has gotten so ridiculous that we really need governments to start dictating how these metrics should be quantified, like they do the fuel-efficiency metrics for automobiles. That's the only way to stop this madness.

I'm not sure I understand your point. Well, at least in theory it's possible for TDP be lower than PPT given only a fraction of PPT is required to sustain base frequency. For example, TDP is 125W, PPT is 170, you put on 125W solution, your CPU starts to draw more than 125W until it reaches a thermal limit during which algorithm will drop frequency and voltage until power draw is reduced at say ~130W which would be sufficient for base frequency. I'm not saying this is the case for ZEN4, i'm saying this is possible in theory. Though it feels to me that 105W for 7700X and 170W for 7900X/7950X should be really enough to sustain base, power scaling shows that 170W gives around 80-85% (if i recall correctly nuilzoid video) performance for 7950X so it seems you can actually even get some boost there. The price is of course CPU is going to be at very high temp.

[piotrj3]

I'm not sure I understand your point. Well, at least in theory it's possible for TDP be lower than PPT given only a fraction of PPT is required to sustain base frequency. For example, TDP is 125W, PPT is 170, you put on 125W solution, your CPU starts to draw more than 125W until it reaches a thermal limit during which algorithm will drop frequency and voltage until power draw is reduced at say ~130W which would be sufficient for base frequency. I'm not saying this is the case for ZEN4, i'm saying this is possible in theory. Though it feels to me that 105W for 7700X and 170W for 7900X/7950X should be really enough to sustain base, power scaling shows that 170W gives around 80-85% (if i recall correctly nuilzoid video) performance for 7950X so it seems you can actually even get some boost there. The price is of course CPU is going to be at very high temp.

TDP is supposed to be thermal design for extended workload, not transient. Of course i don't mind if CPU has temponary higher transient load because thermal mass of radiatiors/coolers will be enough to handle short power spike.

However if extended workload processor consumes more power by 30-40% then TDP indicates, it means AMD's claim is entirly fictional.

Intel actually almost always abides those limits. In Blender/Cinebench/7zip etc. you won't see 12900k consuming for extended periods of time more on average then 241W (+- few watts). Only extreme stress testers like prime95 kind of pushes limit more but i wouldn't call it representative. Meanwhile in Blender AMD made 170W chip push 250W on average in extended period of time. What is more, it is way harder to cool 7950X (comparing to Intel chips) as AMD for some outrageous reason decided to make heat spreader extra tall, and smaller meaning most people can't even make it to 250W without some atrocius setup. der8auer who made direct die cooling (remove heat spreader and put cooler directly on top of chip) decreased tempretures by 22C on 7950X.


arQon Power draw from EPS rail (on average) is kind of equalivent to TDP as essentially all electricity you use is thermal in the end. Of course definition varies but TDP was mostly information made for sake of cooler producers in the past. Since then agressive boosting was introduced Intel dropped TDP and introduced PL1 and PL2 and simply set PL2 either unlimited, or limited in time. And since then with small exception of strong AVX loads/stress testers Intel actually abides it. And AMD with Zen 3 and before was also abiding it up to few watts diffrence.

[Anux]

Intel actually almost always abides those limits. In Blender/Cinebench/7zip etc. you won't see 12900k consuming for extended periods of time more on average then 241W (+- few watts).

But 12900k advertises 125 W TDP.

[piotrj3]

But 12900k advertises 125 W TDP.

https://ark.intel.com/content/www/us...-5-20-ghz.html
No, Intel advertises 125W as "Base frequency" power. It also mentions maximum power draw (241W) for boost loads over periods longer then 1 second (quoting)

Maximum Turbo Power
The maximum sustained (>1s) power dissipation of the processor as limited by current and/or temperature controls. Instantaneous power may exceed Maximum Turbo Power for short durations (<=10ms). Note: Maximum Turbo Power is configurable by system vendor and can be system specific.

Also Intel made it public in 12900k annoucment that for K chips PL2 is no longer time limited, and PL1/PL2 time limits are existing in BIOSes as well as official intel extreme tuning utility (and if you visit data sheet link that is more documented above, you can find them how they work too)

From volume 1

Thermal Considerations
The Processor Base Power (a.k.a TDP) is the assured sustained power that should be
used for the design of the processor thermal solution, Design to a higher thermal
capability will get more Turbo residency. Processor Base Power is the time-averaged
power dissipation that the processor is validated to not exceed during manufacturing
while executing an Intel-specified high complexity workload at Base Frequency and at
the maximum junction temperature as specified in the Datasheet for the SKU segment
and configuration.
Note: The System on Chip processor integrates multiple compute cores and I/O on a
single package. Platform support for specific usage experiences may require additional
concurrency power to be considered when designing the power delivery and thermal
sustained system capability.

So TDP according to Intel is power draw at BASE frequency, without including SoC additional power draw (considering majority of chipset is inside CPU and it is responsible for a lot of IO it makes sense to exclude it). So few watts above power limit (if it happens) comes from IO/SoC related stuff. This happened both for Intel and AMD (5950x by comparison has commonly 105W TDP but likes to load up to 120W, but it is acceptable considering you can't quite count in those watts spent on IO/motherboard etc. related tasks).

But because TDP is useless metric in boosting era of processors intel gave you PL1 and PL2 (and PL3/4 but they are disabled by default) to better represent those loads and in chapter just after one i quoted they are very well described how in general they work. Somewhere there is also information about 12th gen K chips being not limited to PL2.

[coder]

I'm not sure I understand your point. Well, at least in theory it's possible for TDP be lower than PPT given only a fraction of PPT is required to sustain base frequency. For example, TDP is 125W, PPT is 170, you put on 125W solution, your CPU starts to draw more than 125W until it reaches a thermal limit during which algorithm will drop frequency and voltage until power draw is reduced at say ~130W which would be sufficient for base frequency.

Okay, if the base frequencies are computed according to TDP, but the max sustained power draw is PPT, then I can at least understand that.

[coder]

Intel actually almost always abides those limits. In Blender/Cinebench/7zip etc. you won't see 12900k consuming for extended periods of time more on average then 241W (+- few watts). Only extreme stress testers like prime95 kind of pushes limit more but i wouldn't call it representative.

Looks to me like > 150 seconds. That's more than a blip. A lot more.

AMD for some outrageous reason decided to make heat spreader extra tall,

I've read that it was motivated by compatibility with AM4 coolers. If true, definitely not a worthwhile tradeoff!

most people can't even make it to 250W without some atrocius setup.

But they don't have to. Nothing says you need to hit 250 W. AMD didn't guarantee any performance that requires you to dissipate that much power. It's merely a bonus that you can unlock more performance with extreme cooling. That's how I see it. It's a much better situation than AMD building in some completely artificial threshold, IMO.

der8auer who made direct die cooling (remove heat spreader and put cooler directly on top of chip) decreased tempretures by 22C on 7950X.

Direct-die cooling commonly yields cooler temps by more than 10 C. And the hotter the baseline temps, the greater the gains.

[Anux]

No, Intel advertises 125W as "Base frequency" power.

Ah, they must have renamed that at some point, most shops still advertise 125 W TDP.

Thermal Considerations
The Processor Base Power (a.k.a TDP) is the assured sustained power that should be
used for the design of the processor thermal solution, Design to a higher thermal
capability will get more Turbo residency. Processor Base Power is the time-averaged
power dissipation that the processor is validated to not exceed during manufacturing
while executing an Intel-specified high complexity workload at Base Frequency and at
the maximum junction temperature as specified in the Datasheet for the SKU segment
and configuration.
Note: The System on Chip processor integrates multiple compute cores and I/O on a
single package. Platform support for specific usage experiences may require additional
concurrency power to be considered when designing the power delivery and thermal
sustained system capability.

But that again says Processor Base Power = TDP = 125 W. That makes the actual > 200 W much worse.

Don't get me wrong, I don't care what Intel or AMD claim and only look at actual tests for purchasing decisions.

But they don't have to. Nothing says you need to hit 250 W. AMD didn't guarantee any performance that requires you to dissipate that much power. It's merely a bonus that you can unlock more performance with extreme cooling. That's how I see it. It's a much better situation than AMD building in some completely artificial threshold, IMO.

We already had "the cooling solution is the limit" in notebooks much longer. I wouldn't say that I find it good but they give you the possibility to limit it down to 65 W TDP or 88 "real" watts. Possibly with a low end cooler for maybe 35 W it would automatically scale even lower.

[piotrj3]

Looks to me like > 150 seconds. That's more than a blip. A lot more.


I've read that it was motivated by compatibility with AM4 coolers. If true, definitely not a worthwhile tradeoff!


But they don't have to. Nothing says you need to hit 250 W. AMD didn't guarantee any performance that requires you to dissipate that much power. It's merely a bonus that you can unlock more performance with extreme cooling. That's how I see it. It's a much better situation than AMD building in some completely artificial threshold, IMO.


Direct-die cooling commonly yields cooler temps by more than 10 C. And the hotter the baseline temps, the greater the gains.

You know PL2 limits (and stuff like "Multi core enhancment") are set by motherboard manufacturers? This topic was visited by Gamersnexus on previous Intel CPUs (11th and earlier) and they proven when motherboard is set inline with Intel guidelines you won't see 270W. The only reproducable significant outlier on Intel's recommended settings was AVX512 workloads but they are gone on 12th gen.

And again Package power is power of CPU, GPU, chipset related stuff in chip and I/O. Intel power limits are only towards CPU, package power is all of those together.