Explained: How the new BIOS versions are causing higher temperatures

citay

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Note: This thread mostly contains the investigation and explanation for the higher power draw on the latest BIOS versions.
It doesn't go so much into detail about the solution, which can be found in my Guide: How to set good power limits in the BIOS and reduce the CPU power draw.


A lot of people have reported higher CPU temperatures after updating to the latest BIOS version for their 600-/700-series Intel board. Especially after updating to the version containing the 0x129 microcode revision (hotfix for the voltage spike problem with the true 13th/14th gen CPUs), or newer versions.

Now, right from the start, the logical explanation for a higher power draw (when applying the same workload, and if the power limits don't mask anything) would be a higher voltage. But what exactly is causing the higher voltage, which is leading to higher power draw, leading to more heat, leading to higher temperatures?

The hot candidate is "CPU Lite Load", which influences the the CPU voltage via the so-called AC and DC loadlines. The important one is the AC loadline, a voltage added by the BIOS to make up for electrical properties of the CPU socket and such. The background is not so important to understand, the main thing is, the higher this value is, the more voltage is added. This not only takes into account the electrical properties of the board and the CPU socket, it also can make really bad CPU samples run stable (when set appropriately by default), or it can make CPUs be unstable from factory (if set too low by default). Finally, if set too high by default, it will make the CPUs draw too much power and run too hot.

But by what mechanism is there now more voltage added for the CPU? Does MSI choose a higher default mode for CPU Lite Load, and why? I wanted to find out, and since the stable BIOS with the 0x129 microcode just came out for my board model (at the time of writing this), i put it to the test. Now, i am using an i5-13500, so, not a true "Raptor Lake" CPU like a 13600K or 14600K for example (which are definitely affected by the microcode bugs), but an "Alder Lake" 12th-gen-based one. So, it being a 12th gen in disguise, it actually neither needs (nor uses) the newer microcode, it uses Alder Lake microcode instead. But still, i wanted to see if my CPU's voltage and thus power draw also go up.

So, on the old/previous BIOS version, i had CPU Lite Load optimized to Mode 4 for my specific CPU.
This means, Mode 4 is stable for that CPU, with a bit of stability headroom (Mode 3 was verified stable, then i raised it by one step).

First, taking some baseline numbers. The default for "CPU Lite Load" - with my CPU and my board, on the older BIOS version 7D32v1H - was Mode 12:

CPU Lite Load 1H0 Mode 12.png

Click to enlarge

I did some other optimizations there, like enabling all power-saving mechanisms plus Intel Speed Shift Technology. Most of that only lowers idle power draw though.

Then, updating to 7D32v1J:

2024-08-25 18.32.14.jpg


After the update, here's the revised cooler selection screen, which is really the power limit selection screen:

MSI_SnapShot_01 Intel Def.png


I chose the middle option, even though i already knew that - with my cooler and CPU - i would not even reach the middle option's limits. So i also could've chosen the bottom option with the maxed out limits, wouldn't matter in my case. My cooler can easily deal with my CPU's heat, so i could optimize the fan curves for low noise output. But for most people, choosing the middle option "MSI Performance" is a good starting point, from which they can lower the power limits if necessary. Because "MSI Performance" includes the highest power limits that make sense to allow.

MSI_SnapShot_03 MSI Performance.png


Note: The BIOS first has the values for the first option "Intel Default Settings" loaded. So after the middle option is selected, the menu under OC will still show the "Intel Default Settings" values, until you press F10 to save and exit, then the "MSI Performance Settings" are applied. But we know those three options are not that well-fitting for most people anyway, because everyone combines a different CPU with a different cooler. I just chose the middle option because it happens to have the maximum values i would allow for any CPU (even an i9). If there is any thermal throttling with those limits, they have to be optimized to the individual cooling capabilities, which i explain in my guide.

Now, after the update, we're on the new BIOS (the one with the 0x129 microcode). Let's check what the new default settings are. Remember, CPU Lite Load on Auto, in the old BIOS version, resulted in Mode 12. This was still quite high for my CPU, considering it was fully stable at Mode 4. So there's eight steps worth of additional voltage added to VCore, in order to make all CPUs of varying quality work.

Now on the new BIOS:

CPU Lite Load 1J0 Mode 18 defaults.png


Blimey! The new default is Mode 18! I wonder what that will do to the voltages, the power draw, the heat and the temperatures? Nothing good, i can already tell you.
Of course, some other settings were also reset. I enabled them all again manually, but kept CPU Lite Load on Mode 18 for testing.

CPU Lite Load 1J0 Mode 18.png


Now, about the testing, for Cinebench R15, i used Cinebench R15 15.0.37 with Extreme Edition mod, just to explain the oddly low scores for that.

For power draw testing, i mostly relied on an energy meter that's plugged in at the wall socket (actually, at the UPS), for the power cable going into the PSU. This energy meter / power draw measurement device is very exact and, unlike the sensors in the system, cannot be wrong. Additionally i took some measurements from the "CPU Package Power" sensor via HWinfo, which is the CPU-only power draw.

Here is the full comparison:

CPU Lite Load results.png


What can we see from this? All the scores stay basically the same, no matter which mode is active for CPU Lite Load. On some boards, for it to be like this, one would have to disable the "IA CEP Support" setting like i describe in my Guide: How to set good power limits in the BIOS and reduce the CPU power draw. On my board however, this setting is not available (as shown on the screenshots), and with my CPU and board combination, IA CEP clearly doesn't intervene, otherwise the scores would be cut in half with CPU Lite Load Mode 4. But they all stay almost identical within the margin of error.

So, the performance stays the same, but what about the power draw? On the old BIOS, using the default Mode 12 is already quite inefficient. Power draw can be a few dozen Watts higher than it would need to be for this CPU, due to higher-than-necessary Vcore that's applied by Mode 12. So optimizing this setting down to what the CPU actually needs for full stability (in my case, eight steps down to Mode 4) pays off nicely. Everything about how the CPU is running improves, and the scores stay the same. If my CPU was actually hitting a power/temperature limit, then the scores would even improve with Mode 4, because compared to Mode 12, the "power/temperature budget" simply lasts longer, and the CPU can clock higher within those limits.

But now look what happens on the new BIOS, MSI have a new default of Mode 18. This is a catastrophy, now my CPU is not just running eight steps above what it would need for full stability, it's running 14 steps above it! We're seeing 30-50W higher power draw (CPU only, for the whole PC it's up to 90W more) than necessary, and that's just on my lowly i5-13500. On an i7 or i9, the difference would be tremendous, because there are more cores and higher frequencies. And of course, the scores stay the same, the stability stays the same (there is no "more stable than stable"), but everything else has worsened considerably!

So this explains how the temperatures can be so much higher on the latest BIOS versions: The mode for CPU Lite Load has been raised considerably by default. Because it looks like what MSI is doing now is, they're adding a huge safety headroom for the default CPU voltage, most likely in an attempt to stabilize certain CPUs that have already degraded and have a bit of instability.

Their rationale might be, now that there's a voltage limit in place to take care of the voltage spikes, they can happily raise the default voltage (via a higher default CPU Lite Load mode) to stabilize shaky/unstable CPUs, basically the victims of the voltage spike bugs in the microcode. And that actually works for those CPUs that suffered degradation. But for everyone else with a stable CPU, this makes everything a lot worse!

So it has become even more important to try and lower the voltage, otherwise a stable CPU will have needlessly high power draw in all load states, effectively lowering the power and temperature budget and ultimately costing performance. This becomes evident due to instantly improved performance as soon as you undervolt (provided the CPU is hitting a power/temperature limit, which most 14th gen i7/i9 will do unless your cooling is out of this world).

Once you go by my guide, then any higher temperatures can be completely taken care of, because in step 1) you set safe power limits for your cooling, and in step 2) the voltage will be lowered to what your CPU sample actually requires (plus a bit of headroom). This is literally all that is required to bring down the temperatures, either to the level of the older BIOS version when those things were already optimized, or to a better level than ever before if they weren't.

Note: If you undervolted with an offset before (instead of lowering CPU Lite Load), or a combination of the two methods, then the offset undervolt will now happen from a higher baseline voltage. So the best thing in that case is to take note of the previous mode for CPU Lite Load, and apply it again on the new BIOS. The default mode in the newest BIOS version is crazy high! I don't know what they're thinking. Well, i have an idea, but i don't think they're doing anything good by this. For the vast majority of users, the CPU will run worse than before. Going by my guide linked at the very top, this can luckily be reversed.

To round this off, let's look at the "calculation efficiency" of the system in Cinebench R23 with different settings (higher is better):
Old default, CPU Lite Load 12: 119 points per Watt.
New default, CPU Lite Load 18: 100 points per Watt.
Optimized CPU Lite Load Mode 4: 145 points per Watt!

Mode 12 wasn't very efficient to begin with, and the new Mode 18 is just horribly inefficient.
Mode 4, which is still fully stable with my CPU and achieves the same performance, has much higher efficiency.


Lastly, on the far right, i did an additional test, checking the benefits of setting CPU Lite Load to Advanced (using the same AC loadline setting that Mode 4 results in), but optimizing the DC loadline setting so the VID matches the Vcore under full load. In CPU Lite Load Advanced, you can select values for AC and DC Loadline seperately, without having some preset combination which can have the wrong DC Loadline value. So now you can set the DC Loadline so it results in the correct power draw numbers. Doing that involves using HWinfo Sensors, creating full CPU load, then looking at the CPU's VID requests (in the "current values" column), which is the voltage the CPU asks for from the board, and comparing it to the current VCore value. If those are near-identical, the correct DC Loadline value has been found.

VID.png


I have done this, and the result for my CPU on my board was AC loadline 30, DC loadline 117, which can also be read out in HWinfo later:

ACDCloadline.png



The concerns about CPU Lite Load "Normal" (that it won't always show the correct CPU Package Power anymore because the DC loadline is usually not properly adjusted to where it would need to be) are somewhat put into perspective. We have a mere 6W difference from the reported CPU power draw to the "actual" CPU power draw, under the highest load any normal program can create (CB 23 is fully multithreaded AVX load, but Prime95 uses dirty tricks, it's only used for stability testing). This is not gonna make or break out power limits, if we have had to set some.

And even with the reported power draw being slightly off like this on CPU Lite Load "Normal", this doesn't affect us much, we can just go by the maximum CPU temperature to inform us if our power limits are properly dialed in, or if we still need to adjust them according to our cooling. Plus, explaining CPU Lite Load "Advanced" makes it more complicated, which means less people will do it. So i think CPU Lite Load "Normal" is a good compromise.

By the way, this is what resistance/impedance in mΩ (milliOhm) the different CPU Lite Load settings correspond to, valid for both old and new BIOS versions:
CPU Lite Load Normal, Mode 4: AC loadline 0.3 mΩ, DC loadline 0.3 mΩ (this is what i lowered the mode to, verifying that it's stable)
CPU Lite Load Normal, Mode 12: AC loadline 1.1 mΩ, DC loadline 1.1 mΩ (this is the default on the older BIOS versions)
CPU Lite Load Normal, Mode 18: AC loadline 1.7 mΩ, DC loadline 1.7 mΩ (this is the way too high default on the latest BIOS version)
CPU Lite Load Advanced, AC 30 / DC 117: AC loadline 0.3 mΩ, DC loadline 1.17 mΩ (so this way you can set them both directly).
Note: It's possible that some other board/CPU combinations have somewhat different values for a certain mode. They can be read out in HWinfo, as shown above.


Conclusion:
The explanation for the higher temperatures is very simple: Needlessly raised default mode for "CPU Lite Load", causing higher voltage.

Never has it been more important to optimize each Intel CPU in each system individually, according to the cooling and according to what voltage it's running stable with. On the default settings of the latest BIOS versions, the voltage / power draw / heat / temperatures (one influences the next) are higher than ever! With any CPU that is running into power/temperature limits (so, either power limits that you have set to protect your cooling, or failing to do that, the thermal throttling that can happen), the performance will decrease as a result of the new BIOS defaults!

Luckily, with the help of my guide, all those parameters can be improved again: Voltage down, power draw down, heat down, temperatures down, performance identical or up!
This has no downsides other than investing some time for finding good values and testing that it stays stable. Your CPU and your cooling will be very thankful for that effort.
 

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Extremely useful guide! On my board (MSI Z790 gaming plus wifi) the default CPU lite load was 22(!) after the microcode update. Also, all my lite load profiles from 9 to 2 default the DC loadline to 110.

Had to lower my lite load quite a bit, but my 14600kf seems to be liking the load lite 2 (Ac 5 DC 110).
 
Extremely useful guide!

Thank you. Yes, i featured it prominently, because step 2) from the guide is the exact remedy against these unnecessarily high default modes for CPU Lite Load in the new BIOS versions.

On my board (MSI Z790 gaming plus wifi) the default CPU lite load was 22(!) after the microcode update. Also, all my lite load profiles from 9 to 2 default the DC loadline to 110.

Yes, i've actually seen this before, Mode 22 is completely crazy as a default. Almost the highest mode there is, adding tons of voltage! And if your specific 14600KF is running stable at Mode 2, that's an insane 20 steps below the default mode for it. One can only imagine the how badly and inefficiently the CPU would've worked on Mode 22, had you not lowered it. And they just introduced these way higher defaults "through the back door" alongside the crucial 0x129 microcode which people with a CPU such as yours desperately waited for. So i had to write something about it, the situation is unacceptable.

Had to lower my lite load quite a bit, but my 14600kf seems to be liking the load lite 2 (Ac 5 DC 110).

Great result, you seem to have good silicon quality on your CPU sample. Sometimes you somewhat win the silicon lottery like this, other times it may require a higher mode for stability, but very rarely do i see that the default mode can't be lowered, or only by very few steps. Most of the time, a couple steps down are easy to achieve, and with the new sky-high defaults, it seems we're seeing new record numbers of steps it can be lowered. I mean, 20 steps lower, this is for sure the record.
 
Small postscript to the results table: Since i was so focused on the CPU settings, i assumed i had set all my RAM settings like i had them on the old BIOS, but i forgot to manually set "Gear1 mode" for the RAM (explained in my RAM thread), and it defaulted to the slower and less demanding Gear2 mode. This explains the power draw discrepancies between old vs. new BIOS on the same optimized CPU Lite Load setting, especially in Linpack Xtreme (which also stresses the RAM and the memory controller a lot), where it had inexplicably lower power draw on the new BIOS version.

Now that i've redone some of the testing with Gear1 mode active for the RAM, the power draw matches up way better to the older BIOS version on Mode 4. So it was because Gear2 mode for the RAM went easier on it and thus resulted in lower power consumption for that test. And actually, the power draw results for the "Mode 18" tests, especially in Linpack again, would've been even higher with Gear1 mode for the RAM as well.

I will keep the table as it is though, because it's mostly meant to show the huge differences between the default modes and the optimized mode even on my mid-range CPU model, and that it does. Plus i don't feel like re-doing three sets of test runs on the new BIOS, it took me long enough yesterday. But i thought i'd post this additional bit of information at least.
 
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I have an MSI Z790 Gaming Plus Wifi with a i9 14900K in it, limits set to 253w/253w/307a.

Until this week I was on BIOS 7E06vH3 with microcode 0x123
I have now updated to BIOS 7E06vH6 with microcode 0x129

The old bios defaulted to Mode 10 which corresponded to AC 60, DC80
The new bios defaults to Mode 16 which corresponds to AC 110, DC 110

To me, it seems like the new bios is defaulting to intel's recommended 1.1 mΩ and keeping the AC and DC the same.
Yes it might be higher voltage/temp, but isnt this just MSI doing exactly what Intel told them to?
 
Msi godlike max z790 and i9-14900ks. Cpu LL on latest bios w 129, default was 16. I set it to 7 and cinebench 23 score went up at 7. Temps went down to the 70s!
So, after so much concern for many months, I do not understand the default at 16.
Thanks everyone!
 
Excellent work, as usual.

However, I wanted to ask if you had considered exploring the current and the relationship is has with voltage, power and heat?
 
To me, it seems like the new bios is defaulting to intel's recommended 1.1 mΩ and keeping the AC and DC the same.
Yes it might be higher voltage/temp, but isnt this just MSI doing exactly what Intel told them to?

No, as you can see here in the thread already, people get mode 16, mode 18, even mode 22 as the default (i think it depends largely on the CPU model, but then also on the board model). My default was Mode 18, with 1.7 mΩ / 1.7 mΩ. This kind of default is crazy, way too much extra voltage. And this default goes explicitly against the first recommendation table from Intel (even though some of that was later scrapped, see here), where they stipulated this:

Screenshot 2024-08-26 at 23-32-55 MSI Optimized Defaults fried my CPU and it is likely frying ...png


There is no way that this high of a default can be justified with anything. And trust me, this is not for the benefit of the user, this can only ever be for the benefit of Intel and the board makers as i speculated here. On the contrary, the users get screwed over by these high defaults!

Back in April, when it was still early days for the voltage spike issue and nobody knew how to best tackle it other than by applying Intel recommended settings, Gigabyte rushed out beta BIOS updates which can apply an Intel Baseline Profile, but also completely overdid it with the AC/DC loadlines, an article about it is here (Google-translated): https://unikoshardware-com.translat...l=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

They went from an AC/DC loadline default of 0.4 mΩ / 0.9 mΩ (might have been a bit aggressive for some CPUs already) to 1.7 mΩ / 1.7 mΩ, exactly as i was observing on the latest BIOS for my CPU. Trouble is, there are only certain 35W parts where this is allowed, not the normal CPU models most people have!

j-3.jpg


So i don't know what they are trying to do here, but it's not right. One theory, as i said, is that they might want to mask instabilities through the back door like this. If you give an unstable/degraded CPU more voltage, it can perhaps do the job again, at higher power draw of course. Those where the CPU is not unstable will have to suffer from often way too high voltages and power draw for no reason.

Mode 12 default on the old BIOS, ok, 1.1 mΩ / 1.1 mΩ, that checks out. But people, depending on their configuration, are getting defaults now that turns the voltage up to the moon.


However, I wanted to ask if you had considered exploring the current and the relationship is has with voltage, power and heat?

Voltage goes down, power draw goes down. Current is directly related, so it's simple maths. If voltage went down and power draw stayed identical, then yeah, either the current would have gone up, or the power limits played a trick, because if the native power draw (even with lowered voltages) is still higher than the power limits, then only the limits have made sure that the power draw remained the same. At lower workloads where the CPU Package Power doesn't reach the power limits, the power draw would go down accordingly with lower voltages.

Heat, that we only look at for determining good power limits (or if we even require them). Otherwise, the power draw is more interesting, because it directly shows the amount of heat output. Dealing with the heat, that is only up to your cooling. Or did you mean something else?
 
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Msi godlike max z790 and i9-14900ks. Cpu LL on latest bios w 129, default was 16. I set it to 7 and cinebench 23 score went up at 7. Temps went down to the 70s!

Yep, temperatures go down (from lower voltage and thus lower power draw), then performance can go up, especially for a 14900KS.
Glad you got that nice improvement.
 
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Msi godlike max z790 and i9-14900ks. Cpu LL on latest bios w 129, default was 16. I set it to 7 and cinebench 23 score went up at 7. Temps went down to the 70s!
So, after so much concern for many months, I do not understand the default at 16.
Thanks everyone!

What were your temps before?
Did you turn off CEP when changing to mode 7?
 
<SNIP>
Voltage goes down, power draw goes down. Current is directly related, so if the other two go down, it also goes down. If voltage went down and power draw stayed identical, then yeah, either the current would have gone up, or the power limits played a trick, because if the native power draw (even with lowered voltages) is still higher than the power limits, then only the limits have made sure that the power draw remained the same. At lower workloads where the CPU Package Power doesn't reach the power limits, the power draw would go down accordingly with lower voltages.

Heat, that we only look at for determining good power limits (or if we even require them). Otherwise, the power draw is more interesting, because it directly shows the amount of heat output. Dealing with the heat, that is only up to your cooling. Or did you mean something else?

Have you tried setting fixed voltage and frequency to examine variance in current, and the relationship to power and heat?
 
Yep, temperatures go down (from lower voltage and thus lower power draw), then performance can go up, especially for a 14900KS.
Glad you got that nice improvement.
Citay....following your instructions of this thread I changed my CPU Lite Load from Normal to Advanced and copied your settings(since we both have 13500) to AC loadline 30, DC loadline 117. Works like a dream on my system as my system also defaulted to Mode 18 and I did have it manually down to Mode 12. Didn't know how to vary the AC/DC as just changing the Mode makes AC=DC. Thanks for teaching me something new about my system and CPU. Now that I know the change is in Advanced mode a lot of the other posts make more sense now as I couldn't figure out how other people were varying their loadlines. Now I know.
 
Mode 16 on 0x129 BIOS for me is 1.1 ac and 1.1 dc

Yeah, like i said, seems to depend on the CPU too, and the board to some extent. But even this, the equivalent to Mode 12 for my board/CPU combination, has much potential for optimization. The higher the "native" power draw of your CPU (how much power draw it would have under full load when it wasn't limited), the greater the advantage will be when you try to lower the CPU Lite Load mode aka the loadline(s).

Have you tried setting fixed voltage and frequency to examine variance in current, and the relationship to power and heat?

For me, it's enough to look at my energy meter device and CPU Package Power sensor and see how much the power draw goes down when i lower the voltage. Voltage times current, you get the power in Watts. When i know the voltage and the power, i can determine the current. So for this big trend, i don't need to do too much of an examination, just maths.

CPU Lite Load mode 12, CB R24, CPU Package Power: 117W @ 1.178V, current is ~99A (just calculate 1.178 * 99).
CPU Lite Load mode 18, CB R24, CPU Package Power: 135W @ 1.266V, current is ~107A.
CPU Lite Load mode 4, CB R24, CPU Package Power: 102W @ 1.06V, current is ~96A.

Now, of course the CPU (together with the VRM) is more complicated than this, because this is not the entire internal CPU current which something like IccMax is for, it only tells the overarching picture that the current goes down a bit together with the voltage, to result in bigger improvements for the power draw. And my CPU is only a very mild example, because it natively has a relatively low power draw. Once this is done on a more extreme CPU model, that's where the really big improvements will be.

But what you probably mean is something on a small timescale, regarding spikes and such? You're better off asking buildzoid about something like that, with his oscilloscope. All we know for sure is, voltage spikes are the danger. I don't see the current being a danger here, and i don't see current going up, because the power draw comes down so much.


Citay....following your instructions of this thread I changed my CPU Lite Load from Normal to Advanced and copied your settings(since we both have 13500) to AC loadline 30, DC loadline 117. Works like a dream on my system as my system also defaulted to Mode 18 and I did have it manually down to Mode 12.

Good to hear. But just because we have the same CPU model doesn't mean our CPUs are stable at the same voltage. That's why i write in my guide that it has to be found out and tested for each CPU individually, even of the same model, no two CPUs are ever the same. So i would urge you to test and verify the stability yourself. Of course, coming from Mode 18, which probably also means crazy high AC/DC loadlines of 1.7 mΩ / 1.7 mΩ for you, lowering it down to AC loadline 0.3 mΩ will yield sizable improvements, just like it did for me. And when that is fully stable, you have done a good deed for your CPU for sure.

About the DC loadline, this is mostly to get an accurate power reporting via "CPU Package Power" in HWinfo. It also depends on the individual CPU and the board model. For example, recently i was building someone a system using the MSI PRO Z790-A WIFI + i7-12700K, and for accurate power reporting (VID matching VCore under load), the values for CPU Lite Load Advanced were AC 30 / DC 103 (= AC 0.3 mΩ, DC 1.03 mΩ). So there is always a bit of variance in there.

I actually first tested with AC 30 / DC 103 on my system too, just to see if it fits already, but it wasn't a perfect fit yet. For example in CB R23, the VID was 1.062V, VCore was 1.048V. Then later with the values dialed in to AC 30 / DC 117, i got the perfect match in Cinebench of VID 1.048V / VCore 1.048V.

But as i also describe in the text, even if you only use CPU Lite Load Normal and just lower the mode there, then with full load in Cinebench, you still only get an overreported power draw by a mere 6W. So having the DC loadline dialed in exactly is nice to have, but it's not gonna be absolutely crucial. Sure, with a bigger CPU model having a higher power draw, the discrepancy will also get a bit bigger, but even at the full 253W power draw (which i recommend as the maximum for most people), the difference probably won't be bigger than 10-15W or so.

Plus, all that would happen from such slight overreporting of the power draw is that the power limits would be hit slightly early, which is preferable over hitting them slightly late. So the worst thing that can happen is that your temperatures are a tiny bit lower in the power limits, and maybe a smidge less performance when the CPU has to clock ever so slightly lower too. But it's not like dialing in the DC loadline would yield some huge advantage. And when you don't have to set any power limits because your cooling can deal with the CPU no problem (like mine with my 13500), then this slight overreporting with CPU Lite Load "Normal" has no consequence at all.
 
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<SNIP>
For me, it's enough to look at my energy meter device and CPU Package Power sensor and see how much the power draw goes down when i lower the voltage. Voltage times current, you get the power in Watts. When i know the voltage and the power, i can determine the current. So for this big trend, i don't need to do too much of an examination, just maths.

CPU Lite Load mode 12, CB R24, CPU Package Power: 117W @ 1.178V, current is ~99A (just calculate 1.178 * 99).
CPU Lite Load mode 18, CB R24, CPU Package Power: 135W @ 1.266V, current is ~107A.
CPU Lite Load mode 4, CB R24, CPU Package Power: 102W @ 1.06V, current is ~96A.

Now, of course the CPU (together with the VRM) is more complicated than this, because this is not the entire internal CPU current which something like IccMax is for, it only tells the overarching picture that the current goes down a bit together with the voltage, to result in bigger improvements for the power draw. And my CPU is only a very mild example, because it natively has a relatively low power draw. Once this is done on a more extreme CPU model, that's where the really big improvements will be.

But what you probably mean is something on a small timescale, regarding spikes and such? You're better off asking buildzoid about something like that, with his oscilloscope. All we know for sure is, voltage spikes are the danger. I don't see the current being a danger here, and i don't see current going up, because the power draw comes down so much.
<SNIP>

As current is what causes heating of electrical/electronic circuitry, I was just curious as to the relationship between the two, and as current follows voltage, how increasing/decreasing a fixed voltage value impacts the current versus heat.

As you say, voltage is apparently the danger. Setting fixed voltages, as has been suggested by more than one experienced user, may be a viable mitigation.
 
If the proper solution to the CPU degradation problem is a fixed VCore, then Intel might as well pack up altogether. I mean, what are we even talking about then, scrapping a good portion of the CPUs intelligent algorithms? No, if this was something we had to do to be safe, there might be lawsuits left and right, the CPUs would not be what people paid for anymore. That's like a car model having a problem when you push the gas pedal all the way to the floor, and the solution is not to implement some kind of limit or other protection, but instead to drive it with the pedal pushed halfway all the time? Even as an unofficial solution we should expect something better than this.
 
Yeah, like i said, seems to depend on the CPU too, and the board to some extent. But even this, the equivalent to Mode 12 for my board/CPU combination, has much potential for optimization. The higher the "native" power draw of your CPU (how much power draw it would have under full load when it wasn't limited), the greater the advantage will be when you try to lower the CPU Lite Load mode aka the loadline(s).



For me, it's enough to look at my energy meter device and CPU Package Power sensor and see how much the power draw goes down when i lower the voltage. Voltage times current, you get the power in Watts. When i know the voltage and the power, i can determine the current. So for this big trend, i don't need to do too much of an examination, just maths.

CPU Lite Load mode 12, CB R24, CPU Package Power: 117W @ 1.178V, current is ~99A (just calculate 1.178 * 99).
CPU Lite Load mode 18, CB R24, CPU Package Power: 135W @ 1.266V, current is ~107A.
CPU Lite Load mode 4, CB R24, CPU Package Power: 102W @ 1.06V, current is ~96A.

Now, of course the CPU (together with the VRM) is more complicated than this, because this is not the entire internal CPU current which something like IccMax is for, it only tells the overarching picture that the current goes down a bit together with the voltage, to result in bigger improvements for the power draw. And my CPU is only a very mild example, because it natively has a relatively low power draw. Once this is done on a more extreme CPU model, that's where the really big improvements will be.

But what you probably mean is something on a small timescale, regarding spikes and such? You're better off asking buildzoid about something like that, with his oscilloscope. All we know for sure is, voltage spikes are the danger. I don't see the current being a danger here, and i don't see current going up, because the power draw comes down so much.




Good to hear. But just because we have the same CPU model doesn't mean our CPUs are stable at the same voltage. That's why i write in my guide that it has to be found out and tested for each CPU individually, even of the same model, no two CPUs are ever the same. So i would urge you to test and verify the stability yourself. Of course, coming from Mode 18, which probably also means crazy high AC/DC loadlines of 1.7 mΩ / 1.7 mΩ for you, lowering it down to AC loadline 0.3 mΩ will yield sizable improvements, just like it did for me. And when that is fully stable, you have done a good deed for your CPU for sure.

About the DC loadline, this is mostly to get an accurate power reporting via "CPU Package Power" in HWinfo. It also depends on the individual CPU and the board model. For example, recently i was building someone a system using the MSI PRO Z790-A WIFI + i7-12700K, and for accurate power reporting (VID matching VCore under load), the values for CPU Lite Load Advanced were AC 30 / DC 103 (= AC 0.3 mΩ, DC 1.03 mΩ). So there is always a bit of variance in there.

I actually first tested with AC 30 / DC 103 on my system too, just to see if it fits already, but it wasn't a perfect fit yet. For example in CB R23, the VID was 1.062V, VCore was 1.048V. Then later with the values dialed in to AC 30 / DC 117, i got the perfect match in Cinebench of VID 1.048V / VCore 1.048V.

But as i also describe in the text, even if you only use CPU Lite Load Normal and just lower the mode there, then with full load in Cinebench, you still only get an overreported power draw by a mere 6W. So having the DC loadline dialed in exactly is nice to have, but it's not gonna be absolutely crucial. Sure, with a bigger CPU model having a higher power draw, the discrepancy will also get a bit bigger, but even at the full 253W power draw (which i recommend as the maximum for most people), the difference probably won't be bigger than 10-15W or so.

Plus, all that would happen from such slight overreporting of the power draw is that the power limits would be hit slightly early, which is preferable over hitting them slightly late. So the worst thing that can happen is that your temperatures are a tiny bit lower in the power limits, and maybe a smidge less performance when the CPU has to clock ever so slightly lower too. But it's not like dialing in the DC loadline would yield some huge advantage. And when you don't have to set any power limits because your cooling can deal with the CPU no problem (like mine with my 13500), then this slight overreporting with CPU Lite Load "Normal" has no consequence at all.
I tested it last night with some rounds from Cinebench R23 and my CPU is now only getting to 80C tops as it was thermal throttling at 90-101C before(Core boosting) and then just played my games as normal to see how the CPU/system does. Actually does much better, even browsing web, watching youtube with something else open, etc. and considering I'm using the Intel CPU cooling fan that came with the CPU, CPU now stays around 32-34C idle and 76-80C under load. It was staying at 36-38C idle and 84-90C under load.
 
The reason I am asking about amperage; Intel provides documented guidance for three parameters; Power Levels (PL1, PL2), Tau, and Max current.

Does anyone else wonder why Intel makes a point of specifically including amperage? Some motherboards, e.g. Asus, Gigabyte, (unfortunately not MSI) provide a BIOS setting to limit voltage as well. However, Intel provides no guidance on this.

Has anyone tried adjusting only IccMax?
 
If the proper solution to the CPU degradation problem is a fixed VCore, then Intel might as well pack up altogether. I mean, what are we even talking about then, scrapping a good portion of the CPUs intelligent algorithms? No, if this was something we had to do to be safe, there might be lawsuits left and right, the CPUs would not be what people paid for anymore. That's like a car model having a problem when you push the gas pedal all the way to the floor, and the solution is not to implement some kind of limit or other protection, but instead to drive it with the pedal pushed halfway all the time? Even as an unofficial solution we should expect something better than this.

I do not know, but I find that setting VCore to a fixed value in BIOS appears to keep voltages in check, with the caveat that no, I cannot see the transients because I do not have an O-scope. With C-states, Speedstep and Windows Power plan, idle voltages are in the low 0.6 range, load voltages are never over 1.27. I am using the profile for a KS (PL1 = 320, PL2 = 320, IccMax = 400).

So, limiting the VCore also limits the Icc, or not?
 
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