Question Raptor Lake - Official Thread

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Herald

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Jan 23, 2023
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@Carfax83

Have you tried any low wattage cb runs? There is something weird, my 12900k scores 15200 @ 35watts, handily beating the 5950x and edging out the 7950x, but the 13900k scores 15.555 Which is good, but I expected it to scale even more, it basically hits the same score as the 12900k. Wth?
 

Kocicak

Senior member
Jan 17, 2019
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Have you tried any low wattage cb runs? There is something weird, my 12900k scores 15200 @ 35watts, handily beating the 5950x and edging out the 7950x, but the 13900k scores 15.555 Which is good, but I expected it to scale even more, it basically hits the same score as the 12900k. Wth?
I played with the 13900K a lot at lower power limits, I got 16150 at 35W.

IMO the sensible power draw limit for this CPU is something beween 130 and 160W.

I measured two more power limits of 130 and 210W.

View attachment 69233

Compared to 250W, at 130W at nearly half the power draw you lose just 17,6% performance. That is the point at which you could end up if you wanted the chip to run very efficiently but at the same time you wanted high performance.

Here are the decreases in power and performance compared to 250W:

View attachment 69235
 
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Harry_Wild

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Dec 14, 2012
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Only place that the 13500 CPU is available now is AliExpress at MSRP!🫣😱😵‍💫 If you want to buy in U.S., big markup!

I want to buy the 13600 but it not being release in retail channel yet!
 

ondma

Platinum Member
Mar 18, 2018
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I expected 13th gen to blast past my 12900k at 35 watts. It did beat it, but by only 1000 points
The 13900k is faster at higher wattages because of more e cores. Otherwise, it is only slightly faster due to the increased cache and maybe a few other refinements. At 35 watts, it probably is not able to utilize the additional e cores.
 

Carfax83

Diamond Member
Nov 1, 2010
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@Carfax83

Have you tried any low wattage cb runs? There is something weird, my 12900k scores 15200 @ 35watts, handily beating the 5950x and edging out the 7950x, but the 13900k scores 15.555 Which is good, but I expected it to scale even more, it basically hits the same score as the 12900k. Wth?
I just tried it and I got 13,184 o_O

The low wattage combined with my underclock apparently caused this crappy performance LOL! Yeah, I probably should have removed the underclock and undervolt before I did the run..
 

Hulk

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Oct 9, 1999
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I've found 175W to be a good PL1 for my cooling and applications of choice. Most applications that aren't optimized for MT barely hit that number. Presonus Studio One, Photoshop, and most editing operations in Magix Vegas Pro. The only time I notice the CPU really gettin' down to it is when encoding video.
 

Hulk

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Oct 9, 1999
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So here's something I've been wondering. As the process size of these CPU's gets smaller and smaller it seems as though hotspots will become more of an issue. Would it be possible for the Thread Director to distribute the loading of cores so as to not concentrate heat in one location on the die?

For example if an application is only hammering 4 cores instead of employing 4 cores that are physically next to one another, space them out around the die?

Or is the CPU firmware already taking care of this?
 

Herald

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Jan 23, 2023
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I've found 175W to be a good PL1 for my cooling and applications of choice. Most applications that aren't optimized for MT barely hit that number. Presonus Studio One, Photoshop, and most editing operations in Magix Vegas Pro. The only time I notice the CPU really gettin' down to it is when encoding video.
I don't think power limiting the CPU is a great way to use it. RPL gives you so many option on what to do with it that plimit would be the last option I'd use. You can lower the temperature limit from 100c to 85c for example, you can use TVB to drop clocks (and wattage) when the CPU hits a certain temperature etc.

For example, my 12900k was running at 5.4 ghz all core - until it hit 75c, which means that's a heavy MT workload - in which case it dropped to stock 4.9ghz @ 170 watts.

The reason I dislike power limits is that some workloads - even though might draw similar amounts of power, are lighter on the CPU, at least in terms of temperature. For example if you run prime95 at 200 watts vs CBR15 @ 200 watts, the temperatures will not be nowhere close. So i'd rather cap the temperature than the power limit.

Currently im running 85c temp limit - which translates in around 300w peak for bursty workloads, and then it drops to a more sustained 260-270 watts. With an 80c temp limit the sustained limit drops to 230-240w. Ideally I'd like to use 80c as a thermal limit but I have a small single tower cooler, so Im using 85c to not throttle too hard with spikes. If I had a d15 or an fc140 id probably be using 80c

Also I think messing with the clocks on this beast is pointless, the stock clocks are perfect and going over them results in huge voltage increases.
 

Herald

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Jan 23, 2023
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Since some of you are interested, this guy


Tests heavy area of games for his CPU benchmarks, and has a pictures + a description of exactly where he tested, making it easy to validate his results. Sadly he doesn't use RT in cyberpunk - but even without it, a whopping 36% difference between the 3d and the 13900k

cyberpunk.JPG
 
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Hulk

Diamond Member
Oct 9, 1999
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I don't think power limiting the CPU is a great way to use it. RPL gives you so many option on what to do with it that plimit would be the last option I'd use. You can lower the temperature limit from 100c to 85c for example, you can use TVB to drop clocks (and wattage) when the CPU hits a certain temperature etc.

For example, my 12900k was running at 5.4 ghz all core - until it hit 75c, which means that's a heavy MT workload - in which case it dropped to stock 4.9ghz @ 170 watts.

The reason I dislike power limits is that some workloads - even though might draw similar amounts of power, are lighter on the CPU, at least in terms of temperature. For example if you run prime95 at 200 watts vs CBR15 @ 200 watts, the temperatures will not be nowhere close. So i'd rather cap the temperature than the power limit.

Currently im running 85c temp limit - which translates in around 300w peak for bursty workloads, and then it drops to a more sustained 260-270 watts. With an 80c temp limit the sustained limit drops to 230-240w. Ideally I'd like to use 80c as a thermal limit but I have a small single tower cooler, so Im using 85c to not throttle too hard with spikes. If I had a d15 or an fc140 id probably be using 80c

Also I think messing with the clocks on this beast is pointless, the stock clocks are perfect and going over them results in huge voltage increases.
Good points. I forgot that I can lower the throttling temp in the BIOS. Thanks for posting, I'm going to change my methodology on this as I like your reasoning.
 

Hulk

Diamond Member
Oct 9, 1999
3,680
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I don't think power limiting the CPU is a great way to use it. RPL gives you so many option on what to do with it that plimit would be the last option I'd use. You can lower the temperature limit from 100c to 85c for example, you can use TVB to drop clocks (and wattage) when the CPU hits a certain temperature etc.

For example, my 12900k was running at 5.4 ghz all core - until it hit 75c, which means that's a heavy MT workload - in which case it dropped to stock 4.9ghz @ 170 watts.

The reason I dislike power limits is that some workloads - even though might draw similar amounts of power, are lighter on the CPU, at least in terms of temperature. For example if you run prime95 at 200 watts vs CBR15 @ 200 watts, the temperatures will not be nowhere close. So i'd rather cap the temperature than the power limit.

Currently im running 85c temp limit - which translates in around 300w peak for bursty workloads, and then it drops to a more sustained 260-270 watts. With an 80c temp limit the sustained limit drops to 230-240w. Ideally I'd like to use 80c as a thermal limit but I have a small single tower cooler, so Im using 85c to not throttle too hard with spikes. If I had a d15 or an fc140 id probably be using 80c

Also I think messing with the clocks on this beast is pointless, the stock clocks are perfect and going over them results in huge voltage increases.
I've got to thank you for this. I don't know if it was that I never thought about changing the throttling temp or didn't know it was possible in the BIOS but I've been farting around for months trying to find the ideal combination of frequency and power settings for all of my apps! I just booted up, set throttling to 85C as you suggested, reset all that other junk I tweaked, opened up the power limit and boom! All good.
Thanks again.
 

Herald

Member
Jan 23, 2023
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I've got to thank you for this. I don't know if it was that I never thought about changing the throttling temp or didn't know it was possible in the BIOS but I've been farting around for months trying to find the ideal combination of frequency and power settings for all of my apps! I just booted up, set throttling to 85C as you suggested, reset all that other junk I tweaked, opened up the power limit and boom! All good.
Thanks again.
Yeah, temp limit is pretty nice. There are other ways to optimize it depending on what your goals are. Instead of undervolting that lots of people do you can play with the lite loads instead, which will result in lower consumption for lighter workloads while not sacrificing stability for those heavier workloads. Also TVB is pretty insane to use on top or instead of a thermal limit, although it was much more useful for the 12900k than it is for the 13900k.
 

Herald

Member
Jan 23, 2023
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Physics laws reinvented for the sake of clulessness...
Have you ever had a CPU before? Have you actually tested it? If you are running something that pegs 8 cores at 240 watts it will be way harder to cool than something that pegs 16 cores at 240watts, since per core watt is way higher in the first example

Cluelessness indeed.
 

Herald

Member
Jan 23, 2023
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IOW, Watt density is higher in the first case.
Of course, that's what im saying, different workloads will end up with different CPU temperatures even at similar wattages. Just tried it, proof attached, same power limit (150w), exact same fan speeds (you can see fan speeds in HWinfo), CBR23 peaked at 61c CPU Z peaked at 66c. That's a big delta for such a low power limit. I guess I broke physicZ

59c.JPG66c.JPG
 
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Kocicak

Senior member
Jan 17, 2019
752
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The temperature is an internal property of the CPU, the hottest of the many sensors the CPU has inside. It says little about the overall CPU stress or total heat production.

Wattage is something that the CPU cooler must deal with. In the situation you are limited by a cooler, you must set the power draw limit to what the cooler can handle, and not the temperature limit.

Setting the temperature limit is useful if you for example want to prolong the life of the CPU, when you do not believe that 100°C limit by Intel is reasonable.
 
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