# Attempting to mess with Laptop's TDP



## Dranzule (Nov 4, 2021)

So, I've been trying to change my Laptop's TDP. I am aware that Acer is known for locking PL3 on many of their products through the EC, but I wanna be sure. I've been trying to do it through ThrottleStop as XTU doesn't really have anything helpful that TS doesn't have. I have an unlocked BIOS(Insyde H20 Rev 5.0), if that helps. I can mess with Power Limits just fine, but I can still observe throttling when both CPU and iGPU are working to their max extent, as PL2 throttles(goes red for a brief moment, main menu also reports POWER), and it also starts flickering yellow(appearing and disappearing) below CORE sometimes. Increasing it(as in, PL2) didn't really change anything, which lead me to suspect I'm running into some sort of Package TDP Limit. There's no Thermal Throttling going on, PROCHOT only gets triggered in 97°C and TJunction only does so in 100°C.

While slightly unrelated, I also wanted to point out that going into BIOS > Power > Power & Performance > GT - Power Management Control freezes the BIOS completely, and I'm forced to turn the system off. If yall have any idea, could you please share it?

Thanks yall.

Edit: Forgot to point out that my Laptop won't get past 20W even with Power Limits changed. Suspiciously however, I'm fairly certain the Package Limit sits below that.


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## unclewebb (Nov 4, 2021)

Did you check the Lock box? Try clearing that box, press OK, exit ThrottleStop and reboot. If you still see a lock icon on the far left side, that means your BIOS is locking the power limit register. This was common with 6th Gen CPUs.

Post a ThrottleStop screenshot with Limit Reasons open while your CPU is throttling. Does it throttle at 25W or way less? This will show if the EC is setting a much lower power limit.

When Limit Reasons flickers between red and yellow, that means you are right on the edge of power limit throttling. A ThrottleStop log file will show reasons for throttling and power consumption when this is happening.


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## Dranzule (Nov 4, 2021)

>Did you check the Lock box?
Yes. I unlocked it and restarted regardless(for the sake of testing), but results remain similar.

As for the screenshot, I've attached it like you asked. It seems to throttle at 22W, and PL2 flickers between red and yellow at that amount. At slightly lower amounts, like 21W, PL2 will show up(yellow colored) but instead of flickering between yellow/red, it'll just appear(yellow-colored) and disappear.

As for the log, I've uploaded it on Pastebin. I can see PL2 throttling but the power amounts where it throttles seem slightly inconsistent. Maybe it's just the CPU being slightly tolerant of the throttling requests considering the load on top of it?

PS: I ran TS Bench on top of an demanding game to force both the iGPU and CPU to check power limits and see where the laptop would go until it decides to throttle.

PS²: Running TSBench/Cinebench alone pushes the CPU to 14.5-15W which is it's rated limit, although I do not observe throttling on ThrottleStop, it can sit on 3GHZ just fine. While it's also the rated limit, disabling turbo or slightly decreasing clock speeds shows an consistent power decrease(12W) which makes me believe the CPU itself can run on 15W just fine, meaning the throttling might be coming from the iGPU, or the iGPU wants more power than the laptop would allow the package as a whole to receive. I've uploaded a GPU-Z shot putting both the CPU and GPU under load, just in case.


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## unclewebb (Nov 5, 2021)

Dranzule said:


> the power amounts where it throttles seem slightly inconsistent.


The log file confirms that your CPU is throttling at 22W. It looks consistent to me.

```
DATE       TIME    MULTI   C0%   CKMOD  BAT_mW  TEMP    VID   POWER
2021-11-04  19:03:20  29.84   77.8  100.0       0   77   0.9275   21.2
2021-11-04  19:03:21  29.92   73.2  100.0       0   77   0.9305   20.9
2021-11-04  19:03:22  29.91   71.7  100.0       0   79   0.9259   20.9
2021-11-04  19:03:23  29.62   92.3  100.0       0   80   0.9257   21.5   PL2
2021-11-04  19:03:24  29.42   99.8  100.0       0   79   0.9255   21.8   PL2
2021-11-04  19:03:25  29.52   99.8  100.0       0   81   0.9270   21.7
2021-11-04  19:03:26  29.68   99.8  100.0       0   81   0.8965   21.0   PL2
2021-11-04  19:03:27  29.46   99.8  100.0       0   81   0.8860   21.7
2021-11-04  19:03:28  29.39   99.8  100.0       0   80   0.9216   21.9
2021-11-04  19:03:29  29.35   99.7  100.0       0   81   0.9207   22.0
2021-11-04  19:03:30  29.40   99.8  100.0       0   82   0.8676   22.1   PL2
2021-11-04  19:03:31  29.39   99.8  100.0       0   82   0.9232   22.0
2021-11-04  19:03:32  29.44   99.8  100.0       0   82   0.8907   21.9   PL2
2021-11-04  19:03:33  29.39   99.8  100.0       0   82   0.8857   22.0   PL2
2021-11-04  19:03:34  29.37   99.8  100.0       0   81   0.9200   22.1
2021-11-04  19:03:35  29.36   99.7  100.0       0   81   0.9246   22.1
2021-11-04  19:03:36  29.35   99.7  100.0       0   82   0.8953   22.1   PL2
2021-11-04  19:03:37  29.43   99.7  100.0       0   81   0.9235   22.1
2021-11-04  19:03:38  29.40   99.8  100.0       0   81   0.9207   22.0
2021-11-04  19:03:39  29.41   99.7  100.0       0   82   0.8503   21.9   PL2
2021-11-04  19:03:40  29.42   99.8  100.0       0   81   0.9200   22.0
2021-11-04  19:03:41  29.36   99.7  100.0       0   82   0.9169   22.1
2021-11-04  19:03:42  29.39   99.7  100.0       0   84   0.8889   21.9   PL2
2021-11-04  19:03:43  29.37   99.8  100.0       0   83   0.8613   22.0   PL2
2021-11-04  19:03:44  29.33   99.8  100.0       0   84   0.9197   22.2   PL2
2021-11-04  19:03:45  29.35   99.7  100.0       0   82   0.9204   22.1
```

When you are running the CPU right at the power limit throttling point, the CPU is going to be adjusting itself hundreds of times per second. The CPU is being slowed down just enough to keep power consumption under 22W. When power consumption decreases a little, the CPU multiplier goes back up to 30.00. ThrottleStop shows that the maximum multiplier when 2 cores are active is 30. Setting this to 31 in ThrottleStop is ignored by the CPU. You need an unlocked K series CPU to overclock it. 

Your previous screenshot shows that the MMIO power limit has been disabled and the MSR power limits are set to PL1 = 25W and PL2 = 30 W. The log file shows PL2 throttling at 22W so that means the MSR power limit is being ignored. Your computer is likely using an embedded controller (EC) which forces PL2 to 22W. You would have to test for a longer period of time to see what the EC PL1 power limit is set to. The EC might be setting PL1 to 15W long term.

The CPU cores and the iGPU share the same package power limit. When testing with GPU-Z and the TS Bench, open up Limit Reasons to check for throttling. It looks like the CPU cores are being throttled a little. Limit Reasons should be able to report this.

You can try adding this line to the ThrottleStop.INI file to adjust the iGPU power limit.

*IGPU=20*

This will lock the iGPU power limit to 20W. You will need to reboot if you want to change this.

You can also try playing around with the Power Balance feature in the TPL window. This lets you slightly adjust whether the iGPU or the CPU cores will throttle first when the package power limit is reached. Try setting one of these to 31 and the other one to 0 while testing.

You are basically getting about all you can out of your 6500U. Not much room for improvement.


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## Dranzule (Nov 5, 2021)

Yeah, sounds about right. One last question: Would happen to know some way to fool the EC through BIOS settings? I do am aware I can't really change stuff in it(or not feasibly, anyways) so I thought about messing with my power settings a bit.

PS: I have an unlocked one, if that helps


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## unclewebb (Nov 5, 2021)

You need a BIOS option to adjust IMON slope. This tricks the CPU so it reports half as much power consumption. Some MSI boards allow this. Not many other boards do.


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## Dranzule (Nov 5, 2021)

Is this it?


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## unclewebb (Nov 5, 2021)

That is it. Some people adjust both the IMON slope and the offset. I think you can lower the reported power consumption by only adjusting the slope. 

Some boards have a default slope of 100. When set to 50, power consumption will be reported as 50% of actual consumption. 30W will be reported by the CPU as 15W. No more reason for any power limit throttling.

Have fun playing. Run something consistent like the TS Bench and compare different slope settings.


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## Dranzule (Nov 5, 2021)

Well, update(and some bad news, eh)
So, I've messed with IMON slope and offset a bit. Set slope to 50, and, not much changes. Tried also setting offset to 100, 200 and 255, and there's not much change either(well, power varied 0.5w or less, which to me sounds like within margin of error). Did some research and some people are able to set the offset much higher, although mine only goes up to 255. Leaving it at zero doesn't change much either. Also tried setting it to 100-200 and it doesn't change significantly. I thought I could be hitting a power limit instead, so I increased PL1 and PL2 to 35W for the sake of testing, but that wasn't it. Seems like PL2 is still being enforced, despite the slope being changed.

I did benchmarks with both TSBench individually, as well as TSBench + FurMark on the background, to try creating a more realistical scenario(which by itself is still kinda unrealistic) of both components during extreme load. The CPU by itself will only consume 14.5-15W, however it won't report throttling. If the iGPU starts using more power however(to the 22W which we both observed), the system will throttle, which lead me to believe I'm not actually hitting PL2. 
I set IGPU=20 as you suggested and iGPU power usage did go past 10W, and capped at around 12W, which it couldn't do before. I've also messed with the BIOS a bit and took some photos so you have an broader vision of how things are set in the system. Also logged my benchmarking session of me running both TSBench and FurMark. Attachments include the BIOS pics I noted about and a throttling pic during TSBench+Furmark.


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## unclewebb (Nov 5, 2021)

Your screenshot shows that the Package Power is at 24.7W so maybe adjusting the iGPU power limit helped out. Have you tried setting both the MSR PL1 and PL2 power limits in ThrottleStop to 30W?

Did you try adjusting the Power Balance feature in the TPL window yet? If you set this to 31 and 0, this will direct more power to the CPU cores before throttling begins and if you use 0 and 31, that will direct more power to the iGPU compared to the cores. 

In the BIOS, for Power Limit 3 Lock, try changing that from Enabled to Disabled. I think if that power limit is unlocked, ThrottleStop will take care of it automatically. 

Not all settings in an unlocked BIOS are used by the CPU. I am not sure about the IMON Slope and Offset values. It seems like those settings are being ignored. 



Dranzule said:


> I'm not actually hitting PL2


When Limit Reasons shows PL2 in red under the CORE column, the CPU is telling you that you are hitting the PL2 limit. If an embedded controller is set to 22W, all of those power settings in the unlocked BIOS will be ignored and you will still be limited to 22W.


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## Dranzule (Nov 5, 2021)

Yes, I did try messing with Power Balance, it only delayed throttling to another part of my laptop, but since my main issue was a small lack of performance on light gaming, some throttling would still be bad.

I wasn't able to disable the PL3 lock; I randomly decided to update my BIOS as a clutch(Acer Aspire F5 573 723q, went from 1.12 to 1.27) and by sheer luck, I was able to disable the PL3 lock into that version. The EC was updated in it, so who knows what changed in there.

Change was minimal though. I was still hitting some throttling, that in my mind was either related to the package or PL2; Setting IMON Slope on CORE to 50 didn't change anything. Taking my time to think, the system as a whole wouldn't throttle if the CPU or the iGPU were under load; only if both were underload and hitting a certain amount of power. So, I changed the IMON Slope in the Sliced and Unsliced parts of the iGPU, as well as on System Agent, Uncore, and Ring. Now TS reports an 13.6W consumption despite heat generation and voltages being about the same, which suggests to me that the CPU is only reporting half the amount as you have suggested.

The system also doesn't report PL2 throttling under load by both TSBench/Furmark anymore, as you can see in this log.

Attached are benchmarking shots as well as the TPL settings which I changed around a bit. 

PS: I also enabled PL4 in the BIOS, but disabled the lock for it and left it at default(zero).

I consider this an success. Thanks!


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