Question Anandtech.com article on 13900k and 7950x power scaling

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Herald

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Jan 23, 2023
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10 minute run generated a score of 39,709. I opened the window and let some cool air in though while the test was running. I can't say enough good things about the Fractal Design Torrent and the Noctua NH-U12A. An exceptional combo for air cooled setups.

Can hit 42k with the u12a, but I have swapped the stock fans with the T30 :cool:
 
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Herald

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Again you don't understand TDP limits on the different platforms. You can't take a 7950X with a TDP of 105W and compare it to a 13900k with a PL1=PL2=105W and then do efficiency comparisons between the two because they'll use different amounts of power.
Oh come on, of course I do. And yes you are completely right. Problem is, Abwx did the exact same in the last page, nobody seemed to bother. Clearly you see the issue here, no? :p
 

Herald

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That 40W from the video is total system power which is not an accurate way to compare CPU power draw or efficiency. Differences in the motherboard could easily account for most or practically all of that difference. If you look at CPU only power between a 13900k and 7950x for single threaded loads, the difference is in the single digits, i.e., not that significant and no one cares except Intel fanatics who want to find any corner case they can to try and make a case for why Intel CPUs are superior.

View attachment 75260

Oh come on now, TPUP uses CPU only power draw and it shows a 52% efficiency delta. And I wasn't even the one that brought up the review, abwx did, now that it proves how inefficient amd is at doing simple tasks, you discarded the review and going for the next one...

But funny thing, even with the results you just posted , there is still a 30-40% efficiency delta. Compare the wattage with the score and see for yourself.
 

Timmah!

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Jul 24, 2010
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This may surprise you, but because of ray tracing, being CPU limited is much more prevalent now than it has ever been. That HWUB graph has already been heavily critiqued because they never tested any CPU bound scenarios, which is why the graph looks as bunched up as it does.

If you're GPU limited, then the CPU hardly matters at all so why they even bothered with all the testing if it's meaningless in the end? To do proper CPU testing, reviewers need to find the most CPU limited areas in the games and also enable settings like ray tracing which increase CPU dependency. Compare the HWUB graph to something like what PCGH.de does with their testing.

This is a worst case scenario for Zen 4, because The Witcher 3 Next Gen has terrible CPU optimization which makes it hammer 2 cores (due to non native DX12), and when you factor in the BVH calculations from ray tracing and the increased crowd density and draw distances from the next gen enhancements, then it's literally the perfect storm for CPU testing.

Here the 13900K is a good 40% faster than the 7950x at 720p to maximize CPU dependency. Currently, no CPU can maintain 60 FPS in this title at all times and even at 4K you can be CPU bottlenecked.
If you know the game is terribly optimized and uses only 2 cores, this really should not be taken into consideration as a proof some CPU is inadequate. You could take any modern CPU to crawl with Sins of a Solar Empire on big maps with 10 players, only because the game is single threaded. That should hardly make any impact on your decision what to buy nowadays.
If its a modern game like Cyberpunk, that uses 8 or more cores, then fair enough. But Witcher? Meh. I dont know why they even bothered to add RT to that game, i mean it was pretty game back in the day, but nowadays it looks dated, and adding more realistic shadows or GI is not really going to change that.
 

Herald

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If you know the game is terribly optimized and uses only 2 cores, this really should not be taken into consideration as a proof some CPU is inadequate. You could take any modern CPU to crawl with Sins of a Solar Empire on big maps with 10 players, only because the game is single threaded. That should hardly make any impact on your decision what to buy nowadays.
If its a modern game like Cyberpunk, that uses 8 or more cores, then fair enough. But Witcher? Meh. I dont know why they even bothered to add RT to that game, i mean it was pretty game back in the day, but nowadays it looks dated, and adding more realistic shadows or GI is not really going to change that.
Well, although you are not wrong, the question still remains why does that game run better on X cpu while only using 2 cores instead of Y cpu while also only using 2 cores. And the most likely answer is that X and Y cores are not equal, at least not in gaming workloads
 

Hitman928

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Oh come on now, TPUP uses CPU only power draw and it shows a 52% efficiency delta. And I wasn't even the one that brought up the review, abwx did, now that it proves how inefficient amd is at doing simple tasks, you discarded the review and going for the next one...

But funny thing, even with the results you just posted , there is still a 30-40% efficiency delta. Compare the wattage with the score and see for yourself.
You can tilt at windmills for as long as you want, no one is ever going to care.
 
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Hitman928

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Well, although you are not wrong, the question still remains why does that game run better on X cpu while only using 2 cores instead of Y cpu while also only using 2 cores. And the most likely answer is that X and Y cores are not equal, at least not in gaming workloads
Why does that game run better on X cpu while only using 2 cores instead of Y cpu while also only using 2 cores. And the most likely answer is that X and Y cores are not equal, at least not in this particular game but in other games, Y will run better than X.

FTFY.
 
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Hitman928

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The zen4 idle power seems quietly got fixed by AGESA patch long before. I assume some amateur reviewers didn't update BIOS before testing.


Computerbase reported 13-20 watts idle power for Zen4 series while 12900KS has 11 watts idle, at the meanwhile CB R23 1T burns roughly the same watts for 7950X and 12900KS. Although CB 1T is not a good test and doesn't reflect realworld performance, IMO.


I don't know why this become a debatable topic suddenly.

That's easy, see post 163
 

Herald

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You can tilt at windmills for as long as you want, no one is ever going to care.
Oh dont worry, ive noticed that. Nobody cares about facts around here, they are busy trying to convince me that their cpu of choice saves them 300 watts per hour over the other cpu. And thats an actual quote. But nobody seems to disagree with that, so you know, whateva.
 

Markfw

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Oh dont worry, ive noticed that. Nobody cares about facts around here, they are busy trying to convince me that their cpu of choice saves them 300 watts per hour over the other cpu. And thats an actual quote. But nobody seems to disagree with that, so you know, whateva.
No, we care about facts. You are the one who can't read or accept facts.
 

Kocicak

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Jan 17, 2019
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Back to the original article, what are those numbers in the graphs? It is not clear. Is it the real power consumption?

It is easy to measure Intel procesor performance at given power limit, because that is what is set in bios and the cpu holds that value precisely. With AMD I am not sure, that you can set the power limit in Watts, but with Amperes, which would result in some not so round power consumption numbers.

Without knowing this the article is worthless.

The most efficient to date are AMD monolithic processors 5600G and 5700G.

Non monolithic AMD processors suck in idle and light load and excel in heavy MT load.

Monolithic Intel CPUs are great in light to normal load, and suck slightly in heavy MT load while being limited to sensible power consumption, and suck more when being unlimited.

 
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Herald

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Back to the original article, what are those numbers in the graphs? It is not clear. Is it the real power consumption?

It is easy to measure Intel procesor performance at given power limit, because that is what is set in bios and the cpu holds that value precisely. With AMD I am not sure, that you can set the power limit in Watts, but with Amperes, which would result in some not so round power consumption numbers.

Without knowing this the article is worthless.

The most efficient to date are AMD monolithic processors 5600G and 5700G.

Non monolithic AMD processors suck in idle and light load and excel in heavy MT load.

Monolithic Intel CPUs are great in light to normal load, and suck slightly in heavy MT load while being limited to sensible power consumption, and suck more when being unlimited.
To be honest, you cant measure either amd or intel by hwinfo reports. Intel are accurate only if you fix your ac dc loadlines so vid matches vcore. Amd, at least with zen 3, were completely inaccurate due to mobo manafacturers cheating with their power reporting deviations.

Now with that said, both the 7950x and 13900K are very inefficient out of the box compared to the 5950x. If you power limit them on the other hand they are both incredibly efficient in mt workloads so whoever is complaining has an agenda that is trying to push. And usually those people support one specific company over another 😊

With that said yeap, the monolithic amds are pretty insane, got them on my laptop and they are great. I dislike the amd gpu software whatever its called, but other than that its pretty great
 

Carfax83

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Nov 1, 2010
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The zen4 idle power seems quietly got fixed by AGESA patch long before. I assume some amateur reviewers didn't update BIOS before testing.


Computerbase reported 13-20 watts idle power for Zen4 series while 12900KS has 11 watts idle, at the meanwhile CB R23 1T burns roughly the same watts for 7950X and 12900KS. Although CB 1T is not a good test and doesn't reflect realworld performance, IMO.


I don't know why this become a debatable topic suddenly.
I don't think anyone has brought up idle power usage in this thread o_O

What's been mentioned are the low to moderate CPU usage workloads like browsing and other apps where it appears RPL has an advantage over Zen 4 in terms of power draw and performance per watt.
 
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Carfax83

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Can hit 42k with the u12a, but I have swapped the stock fans with the T30 :cool:
Is that with a 10 minute run or a single run? My CPU is undervolted and underclocked, and the highest score I've gotten was 40,200 at 235w and 5.3ghz. I decided to undervolt and underclock my CPU because I primarily use my machine for 4K gaming and occasional encoding. Not really into benchmarking.

I'll have to look into those T30 fans though. Watched a review and it appears they can really lower the temps substantially! If I swapped them out, I may be able to increase clocks to 5.4ghz while still staying under 250w.

The Noctua NH-U12A is a mighty little beast!
 

Herald

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Is that with a 10 minute run or a single run? My CPU is undervolted and underclocked, and the highest score I've gotten was 40,200 at 235w and 5.3ghz. I decided to undervolt and underclock my CPU because I primarily use my machine for 4K gaming and occasional encoding. Not really into benchmarking.

I'll have to look into those T30 fans though. Watched a review and it appears they can really lower the temps substantially! If I swapped them out, I may be able to increase clocks to 5.4ghz while still staying under 250w.

The Noctua NH-U12A is a mighty little beast!
10 minute it drops to 41500 roundabout.

Yeah the t30 should give around a 4 to 6c decrease at max rpm but they are noisy as hell at those rpms. But still it handles 330w at 95c without throttling which is impressive

Just realised i got down voted for saying I can hit 42k. That is hilarious 😂
 

Carfax83

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If you know the game is terribly optimized and uses only 2 cores, this really should not be taken into consideration as a proof some CPU is inadequate. You could take any modern CPU to crawl with Sins of a Solar Empire on big maps with 10 players, only because the game is single threaded. That should hardly make any impact on your decision what to buy nowadays.
If its a modern game like Cyberpunk, that uses 8 or more cores, then fair enough. But Witcher? Meh. I dont know why they even bothered to add RT to that game, i mean it was pretty game back in the day, but nowadays it looks dated, and adding more realistic shadows or GI is not really going to change that.
The problem with that though is that the Witcher 3 is one of the most popular PC games of all time, so you can't really just ignore it. Literally millions of PC gamers are playing the game, and the update was completely free and added significantly to the overall look and feel of the game. The original game looks absolutely dated compared to the Next Gen release and this is despite that the Witcher 3 was never designed around ray tracing at all in terms of assets. I agree essentially though that it's not really evidence that a particular CPU is inadequate, because the game is clearly very inefficient with how it uses the CPU.

The reason why I uploaded that graph was to show how the architectural differences between RPL and Zen 4 can affect performance output in massively CPU bound scenarios that include ray tracing.
 

DrMrLordX

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Apr 27, 2000
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Utilizing an environmental temperature of 51F/10.5°C to augment your cooling and then claiming "air cooling" is a bit disingenuous.
Hey smoke em if you got em. If I were able to utilize geocooling for my PC 24/7 you know I would. But yeah abnormal ambients do need to be taken into account.

Oh come on, of course I do. And yes you are completely right. Problem is, Abwx did the exact same in the last page, nobody seemed to bother. Clearly you see the issue here, no? :p
1). I'm not having this conversation with him
2). Plenty of people have given Abwx trouble about his posts in the past, and sometimes he even deserved it. You (apparently) weren't here during the pre-Zen era.
 

Herald

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1)I'm not having this conversation with him
2). Plenty of people have given Abwx trouble about his posts in the past, and sometimes he even deserved it. You (apparently) weren't here during the pre-Zen era.
That is exactly the problem. That you are not having this conversation with him. Or with the guy mentioning he saves 300w an hour per day by going amd. Or with a myriad other posts that said something that is just not true, but get a freepass cause they are defending amd. I intentionally used unfair comparisons to see who would try to correct me but not the other posts that do the same but where defending amd instead.

Besides hitman who had a more objective view of things and i agree with pretty much everything he said, the rest of the posters were... Lets just say, not deploying facts but fantasy.
 

Carfax83

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Yeah the t30 should give around a 4 to 6c decrease at max rpm but they are noisy as hell at those rpms. But still it handles 330w at 95c without throttling which is impressive
It's incredible that a relatively small heatsink can dissipate 330w of heat! :eek:

Did you tweak the voltages at all? And what case are you using?

Just realised i got down voted for saying I can hit 42k. That is hilarious 😂
You've developed quite a cult following it seems. This forum generally speaking leans heavily towards AMD. It wasn't always that way in the past during Anandtech's golden age, but Intel's chronic 10nm issues and delays combined with Skylake fatigue helped fuel Zen's meteoric rise so that it has a strong fanbase on the Anandtech forums. And to be fair, Zen 2 and Zen 3 were much better CPUs overall than their Intel counterparts at the time.

I myself skipped Skylake entirely due to being fed up with small performance improvements and nearly upgraded to a Zen 3 rig, but I held out in the end for a massive Broadwell-E to Raptor Lake i9 upgrade.
 
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Herald

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It's incredible that a relatively small heatsink can dissipate 330w of heat! :eek:

Did you tweak the voltages at all? And what case are you using?
Im using the same case as you 😁

Swapped the bottom fans though but that shouldnt make a difference in cpu temps.

No voltage tweaking, my ecores are a dud, they crash at heavier workloads when undervolted so im running stock. I mean sure i could make the cpu CBR23 stable only and post some fancy numbers but what's the point 😊
 
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Herald

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've developed quite a cult following it seems. This forum generally speaking leans heavily towards AMD. It wasn't always that way in the past during Anandtech's golden age, but Intel's chronic 10nm issues and delays combined with Skylake fatigue helped fuel Zen's meteoric rise so that it has a strong fanbase on the Anandtech forums. And to be fair, Zen 2 and Zen 3 were much better CPUs overall than their Intel counterparts at the time.

I myself skipped Skylake entirely due to being fed up with small performance improvements and nearly upgraded to a Zen 3 rig, but I held out in the end for a massive Broadwell-E to Raptor Lake i9 upgrade.
Ive also bought every single zen cpu except zen 3, but nowadays intel offers much better products for my needs. But mentioning that gets some people triggered it seems
 
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Herald

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This cannot be true. I would belive 240, but not 330, that is something that even some small water coolers cannoot handle.
I've posted a ycruncher run at 330w in the rpl thread. You can check it.

It can do more than 330 but i thermal throttled it at 95c instead of a 100
 

Markfw

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That is exactly the problem. That you are not having this conversation with him. Or with the guy mentioning he saves 300w an hour per day by going amd. Or with a myriad other posts that said something that is just not true, but get a freepass cause they are defending amd. I intentionally used unfair comparisons to see who would try to correct me but not the other posts that do the same but where defending amd instead.

Besides hitman who had a more objective view of things and i agree with pretty much everything he said, the rest of the posters were... Lets just say, not deploying facts but fantasy.
I even included graphs proving my point, but again, you ignore any facts that don't fit your fantasy.

Here: https://forums.anandtech.com/threads/anandtech-com-article-on-13900k-and-7950x-power-scaling.2609753/post-40937527
 
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Kocicak

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95°C means that the cooler already cannot dissipate the heat the CPU produces easily. It struggles.

How much heat can it dissipate if you wanted the CPU to be 70°C?
 

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