MSI Z890 Carbon Wifi Power Limit Throttling

[mduvenag151102d2]

HI there, not sure I'm posting this in the right place but when running Intel Extreme Tuning Utility and doing a stress test I get a Power Limit Throttle, just wondering if anyone has any info on this?
Tried running Standard and performance profiles in bios.
My spec are:
Intel 285K
MSI Z890 Carbon Wifi
Asus Stix 4090 OC edition
Super Flower Leadex VII XG 1300W
Arctic LF 420
Asus ProArt PA 602 Case
96GB (2x48GB) Trident Z5 RGB Series DDR5-6400 CL32 1.35V
Windows 11 Pro
Samsung 990 Pro 4TB
Samsung 990 Pro 2TB
Crucial T705 1TB PCIe 5.0 x4 NVMe

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[citay]

Wow, finally someone with a Core Ultra, i think you are the first one that i see here more or less! Intel must hardly sell any of them...

Anyway, power limit throttling is not unusual, it's much better than thermal throttling. Basically, during a stress test, every higher model of CPU will be throttled in some way nowadays. If there are no power limits set, then especially the high-end CPU models will overpower the cooling capabilities which would result in thermal throttling, an emergency mechanism to prevent the CPU from completely overheating. So power limits, restricting the maximum power draw, is much preferred, they are preventing the temperatures to get out of hand in the first place.

Now, not having seen such a system first-hand before, i'm curious as to what power limits are set here. To find out, you can go by my Guide: How to set good power limits in the BIOS and reduce the CPU power draw, especially step 1) for now. Meaning, run Cinebench (i tend to use R23, should be linked in there) and run HWinfo alongside, with the sensors expanded. That would show exactly how this system is behaving, where the limits are, how your cooling is coping with the heat, and so on. The Arctic Liquid Freezer III 420 you have there, i assume? Very mighty AIO, i expect quite low temperatures. Don't set your individual power limits yet, let's first see what the BIOS defaults to with the Performance preset.

BTW, make sure you are on the latest BIOS: https://www.msi.com/Motherboard/MPG-Z890-CARBON-WIFI/support
Yes, the beta. All the versions are beta for now, the BIOS is still quite immature, that's how it is as an early adopter.

About Intel XTU, i never use that, you don't really need it. Most relevant things i would set directly in the BIOS, and for monitoring, HWinfo is where it's at.

 

[mduvenag151102d2]

Wow, finally someone with a Core Ultra, i think you are the first one that i see here more or less! Intel must hardly sell any of them...

Anyway, power limit throttling is not unusual, it's much better than thermal throttling. Basically, during a stress test, every higher model of CPU will be throttled in some way nowadays. If there are no power limits set, then especially the high-end CPU models will overpower the cooling capabilities which would result in thermal throttling, an emergency mechanism to prevent the CPU from completely overheating. So power limits, restricting the maximum power draw, is much preferred, they are preventing the temperatures to get out of hand in the first place.

Now, not having seen such a system first-hand before, i'm curious as to what power limits are set here. To find out, you can go by my Guide: How to set good power limits in the BIOS and reduce the CPU power draw, especially step 1) for now. Meaning, run Cinebench (i tend to use R23, should be linked in there) and run HWinfo alongside, with the sensors expanded. That would show exactly how this system is behaving, where the limits are, how your cooling is coping with the heat, and so on. The Arctic Liquid Freezer III 420 you have there, i assume? Very mighty AIO, i expect quite low temperatures. Don't set your individual power limits yet, let's first see what the BIOS defaults to with the Performance preset.

BTW, make sure you are on the latest BIOS: https://www.msi.com/Motherboard/MPG-Z890-CARBON-WIFI/support
Yes, the beta. All the versions are beta for now, the BIOS is still quite immature, that's how it is as an early adopter.

About Intel XTU, i never use that, you don't really need it. Most relevant things i would set directly in the BIOS, and for monitoring, HWinfo is where it's at.

Hi, Yes it seems to be a thing that I'm one of the few who have a Core Ultra but for my needs, Premiere Pro specifically it's a great CPU and the extra IO on the Z890 boards is perfect for me.

Thanks so much for explaining that so well, that all makes sense now. Very much appreciated.

I'll go through your guide and share the results with you, I have the latest Bios installed, thanks for that. The Ez Flash Bios button is awesome!

Good to know about XTU! I'll get HWinfo instead.

I really appreciate the help with this, It's been a while since I built a system.

 

[mduvenag151102d2]

Here are the screengrabs from HWiNFO

 

[citay]

Yes, this is how i imagined it, pretty much. All seems as expected. Power limits are quite high, no doubt due to the "MSI Performance" preset. Because normally, Intel allows 250W for the Core Ultra 7/9, but MSI pushed it further to allow 295W for up to a minute or so. You see this in the middle of the first column, PL1 / PL2 power limts. We can also see that your CPU - if the sensors are to be believed (CPU Package Power) - natively draws a bit over 260W. So that Long Duration Power Limit (as it's called in the BIOS) of 250W, it only ever so slightly comes in after the minute is up. So, compared to a 14900K for example, we have a still enormous, but certainly less extreme power draw.

Your CPU cooler is doing a great job too, keeping this in the 80°C range with this amount of heat. So you don't really need to change much about the power limits here. Normally i say, i would never allow more than 250W for any CPU, because above it is "junk performance". But seeing how you "only" have 260W natively, we won't make too much of a fuss about that. Instead what you can attempt, try step 2) from my guide. MSI themselves are now saying how useful this setting can be, here's an example from the marketing of their new Z890 boards:

I explain that all in my guide. You basically try to lower the mode for this "CPU Lite Load" setting while keeping full stability. At some point you will get the first sign of instability in a stress test (i link a couple in there), then you raise the mode again to the last stable one and test that extra well. If it's confirmed stable everywhere, i would raise the mode by another step to have stability headroom. But even with that, the mode should then be much lower than whatever the default was, netting you significant improvements in how the CPU operates.

 

[mduvenag151102d2]

Just wow! Thank you so much for this amazing knowledge you are sharing!
I feel much better knowing that my system is not running terribly, I'll move on to the next step then and see how that goes. I'll let you know once I have success, which might take a while.
Anyhow thank you once again, I can't thank you enough.

 

[mduvenag151102d2]

Have the CPU Lite Load at Mode 5 and stable, I will try lower settings tomorrow but for now completely stable.
I will send new HWiNFO screengrab at mode 5, bear in mind I ran prime95 1st and then straight into Cinebench R23, no real performance drop.
Awesome!

 

[citay]

Nice. And here we come to a peculiarity of Core Ultra, in that it's not entirely clear how trustworthy those power draw numbers are in HWinfo, since Intel has completely changed how the internal CPU voltages are regulated. The CPU manages that much more by itself now. Reviewers have mentioned this as one of the big problems of testing these CPUs, since not only might those sensors not accurately show what is going on, but also, unless a power test bench is used, you can't tell the precise CPU power draw anymore.

Of course, for normal users, this is not feasible. So the best you can do at home would be to use an energy meter that's plugged in at the wall socket, for the mains cable going into the PSU. Unlike the sensors in the system, this cannot be wrong. Of course it will show the power draw of the entire PC, yes, but then you would just compare it to baseline numbers you recorded before and see if the power draw under full load has gotten lower. A device like this:

But even that energy meter is probably not so widespread. So in your case, we can mainly rely on the way we know this CPU Lite Load to work: It lowers the AC/DC loadlines, and especially the AC loadline determines how much voltage the CPU uses for certain frequencies. Your lower it, and it should lower the voltages, which should lead to lower power draw and all the rest of the good stuff.

Now, if you happen to have such a device or are willing to get one (they are very cheap, i'm talking 10-20 bucks for a decent one), that would show more of what's going on. Otherwise, yeah, we have to put our trust that this works as advertised. You are a pioneer in testing these optimizations on Core Ultra, so i don't have any empirical data to rely on.