Power limiting a 12600K

fuyume · Jun 14, 2022

I am building a passively-cooled system, and while I was originally planning on getting a 12600T, I had so many problems trying to get one that I decided, after consultation with Noctua, to order a 12600K and manually limit PL1/PL2/Tau in the BIOS, and possibly undervolt it, as well. So, I've hoping to hear from others who may have done similar things. Most of the talk on enthusiast forums is about wringing every last possible bit of performance out of a system.

I'm using a Thermaltake Core P3 chassis, Gigabyte Z690 UD AX DDR5 motherboard, Seasonic PX500 fanless PSU, and Noctua NH-P1 CPU cooler. It's been 8-9 years since I last built a PC from scratch, and that was a Haswell Core i3 for my niece and nephew.

Since the 12600T's PL1/PL2/Tau values are 35/74/28, I thought I would start there, but the 12600K has the 4 efficiency cores that the 12600T doesn't have, so I am guessing I should probably bump up those numbers at least slightly. The NH-P1 cooler should have enough headroom for a modest increase. Noctua does rate the NH-P1 as being compatible with the 12600K, so long as you don't mind a bit of throttling, and rates it as having "limited overclocking headroom" for the 12600T.

Since I am going to be dramatically lowering the power limits, and hopefully undervolting by a bit to further reduce TDP, this should theoretically work.

Kaltenbrunner · Jun 15, 2022

Welcome aboard, those are low starting numbers, and I'm guessing an easy load for your cooler.

Yeah I just got a 12700k working, and after installing new BIOS, the defualt setup up was using way too much power, and I didn't look hard enough in the BIOS to realize it.

This guy here know a bunch about OCing, so now I'm trying to find my voltage-frequency curves for my OC. I had really bad thermal paste too, just got new stuff on there and lowered my temps by another 10C or more under load.

Paradigm Shifter · Jun 15, 2022

Given that the P1 is a passive cooler, I'm not sure I'd want to push any Alder Lake chip too much if you're planning on sustained loads.

As you suggest, while it might mean a crash or two, I'd start with the 12600T numbers; if they work then you're laughing, and can iterate from there.

I'd either do initial testing using Linux (which is more sensitive than Windows to instability, in my experience) or don't activate Windows (or get everything set up, then clone the disk for easy recovery) just in case a crash or background instability results in data corruption...

fuyume · Jun 15, 2022

Paradigm Shifter said:
Given that the P1 is a passive cooler, I'm not sure I'd want to push any Alder Lake chip too much if you're planning on sustained loads.

As you suggest, while it might mean a crash or two, I'd start with the 12600T numbers; if they work then you're laughing, and can iterate from there.

I'd either do initial testing using Linux (which is more sensitive than Windows to instability, in my experience) or don't activate Windows (or get everything set up, then clone the disk for easy recovery) just in case a crash or background instability results in data corruption...

Yeah, I'm more than likely going to do the initial build under Linux, just because it's easier. I do have a spare Windows 10 Pro license that is upgradable, but this will be the first system I own that's capable of running Win11.

And I'm not planning on pushing it, at all. This PC is meant for relatively light duty tasks as my bedroom entertainment system hooked up to the 50" TV at the foot of my bed. Media storage and playback, light gaming, occasional work, but that's about it. I'm more concerned about power usage, noise level, light levels, and reliability.

ThatGuyJD · Jun 15, 2022

Don't understand the start at the 12600k, a 12600 or even a 12400 which is significantly closer to the 12600T specs than the 12600k would work as well. Otherwise starting at the power limits for the 12600T would be good and just set lower multiplier it should work fine.

Paradigm Shifter · Jun 15, 2022

fuyume said:
Yeah, I'm more than likely going to do the initial build under Linux, just because it's easier. I do have a spare Windows 10 Pro license that is upgradable, but this will be the first system I own that's capable of running Win11.

And I'm not planning on pushing it, at all. This PC is meant for relatively light duty tasks as my bedroom entertainment system hooked up to the 50" TV at the foot of my bed. Media storage and playback, light gaming, occasional work, but that's about it. I'm more concerned about power usage, noise level, light levels, and reliability.

I'll be honest, unless you have a specific use-case for Windows 11 (e.g.: WSL2 or CUDA-on-WSL2) I just wouldn't bother with it right now.

Noisiest bit with be HDDs, if you're using them for media storage.

rluker5 · Jun 16, 2022

There are more tools available for controlling your power use if you are using W10 or W11. If you just want to get bios parameters for clocks and power limits I'd recommend downloading HWinfo64, CPUz, some stress tests and doing an offline, unactivated windows usb install if you didn't want to assign your key to this pc right away. Get yourself some stable undervolt, even if it runs a little hot, then adjust your clocks using Windows power plans like I demonstrated here: Windows Power Plan Unleashed! (but still a little messy) | Overclock.net

The amount of power Alder uses is extremely dependent on clocks and Windows will use higher clocks and power than it needs to. You can put a decent load on your chip and adjust it's clocks and see the difference in power consumption in real time. Both the P and E cores have their own volt/frequency curves and if one of them calls for higher volts they both get it. I try to set the P cores to what volts/power I want and then adjust the less important E cores so they are as fast as can be without raising the volts.

Doing this you can see just what max clocks you want in your bios, or you can just set your bios faster, but still in the efficient range, then just choose a different power plan with different clocks depending if you want your chip hotter and faster or cooler and slower.

fuyume · Jun 22, 2022

The motherboard finally came in yesterday, and the system is built.

I have set in the BIOS Package Power Limit 1 to 40 Watts, Package Power Limit 2 to 80 Watts, and PPL2 Time to 40 seconds. Those are the only settings I changes in the BIOS. ANd they seem to be reported correctly in HWInfo. Windows 11 Power Setting is 'Maximum Power Efficiency". IDK why it shows up as Windows 10 in Cinebench.

During this run of Cinebench R23, according to HWMonitor, CPU temp never exceeded 50C and power consumption never exceeded 40 Watts.

I'm pretty pleased, so far. The system is dead silent, and handles 2160p60 easily, with four simultaneous instances of Bluestacks 5, each set to 2 cores, 4 GB RAM, and 30 fps.

Font Screenshot Multimedia Electronic device Software

fuyume · Jun 22, 2022

Here's the system before I put the glass panel on the front:

Table Personal computer Desk Computer hardware Computer case

fuyume · Jun 23, 2022

After playing around with some of the Power Limit settings and not reaching dangerous territory, I decided to load the BIOS defaults and let her rip.

Cinebench R23 Multi-Core = 17485, about a 56% increase over my first try. Temps reached 96-97 C at the 9 minute mark, but never went any higher, and recovered almost instantly once the test finished. Maximum power draw was about 127 W, with it hovering between 120-125 W for most of the duration of the run. Presumably, since the test only runs to 10:00 plus whatever time is takes to finish the last scene, it might continue to get hotter until it started throttling at 100 C, under sustained load, but for now I'm going to run like this and monitor it under daily use. To say I am impressed with the capabilities of the Noctua NH-P1 would be an understatement.

In the long term, I may end up limiting it slightly, just to be safe, since I have no aircon in my house, and it usually hits as high as about 32 C ambient during the height of the Summer in my bedroom, where this system will live. It's only 21 C outside, right now, maybe 25 C inside. Of course, in the Winter, I keep my heating system set to only 18 C to save heating fuel, so the system will act as a low powered space heater in my bedroom.

I am little confused as to why, in the Gigabyte BIOS, there is a setting for "Package Power Limit" and a setting for "Platform Power Limit". I have not touched the latter. Also, it's confusing why there is a "Package Power Limit 1 Time" (which HWInfo64 reports as 8 sec when set to Auto) and a "Package Power Limit 2 Time" (which HWInfo64 reports as 2.4 ms when set to Auto). To add to the confusion, when I set Turbo Power Limits (the whole category) to Auto, HWInfo64 still reported the previous custom settings. That's why I went ahead and did a BIOS defaults reload.

There doesn't seem to be any documentation of the differences in what these settings do, that I have been able to find.

What I think should be pretty obvious from these tests is that there is a diminishing return to adding power to the CPU, if it can achieve 62% of its maximum performance while running on 32% of its maximum power.

And with this system being absolutely dead silent 0 dBA noise, the fan noise of my 2017 MacBook Pro from 1.5 metres away is driving me crazy, and that machine is just idling!

Power limiting a 12600K

fuyume

Kaltenbrunner

Paradigm Shifter

fuyume

ThatGuyJD

Paradigm Shifter

rluker5

fuyume

fuyume

fuyume

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