Weird 8750h behavior after touching TPL parameter!

[scarpinoc]

Hello guys,

I'm new here (Italy), but I'm a bit expert about PCs. I assemble PCS, and repair laptops.
The next story is long, sorry ^__^


I have a MSI GF75 Thin laptop with 8750h CPU.

--------------------
PART 1

I played with TS 9.4 a bit and I was able to get not bad score: CPU core -260 and CPU Cache -130.

I was happy... R23 was in full load (3.9Ghz) for 10 minutes with some drop to 3.8Ghz. 7100 points, not bad for such old PC.

--------------------
PART 2

Then, I decided to play with TPL parameters. Here problems started...

I don't remember what changes I did, but, I see that the PL2 starts much earlier and the clock is almost fixed to 3.5 Ghz after 20-30 seconds of 3.9! Really fixed, with temperature low (78-82°C).

Ok, I delete the .ini file, turned off PC, wait 1 minute, turned on again and start again TS with ONLY CPU core -260 and CPU Cache -130 (confirmed by CPUID HWMonitor, voltages are zeroed)

Believe me or not, I have the same behavior: clock speed stuck ad 3.5!

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PART 3

So, after one day of tried and errors, I formatted, installed all software, and configure the PC (almost one day of job!), and all was fine! Stable PC, good clock 3.8-3.9,

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PART 4

Then, I played a little bit with TPL parameters and, again, I'm in the same situation. I run Corona Renderer benchmark or R23, and I see clock stuck at 3.5 after 20-30 seconds of 3.9 (because l reduced voltages with TS).


Now, if I deleted the .ini file, turn OFF the PC, turn on, and DON'T turn TS, in R13, my PC run ONLY 2.73 with max temp at 95, so I go in thermal throttle!!!
It's like TS did something in Windows 10, and Windowes 10 remember these settings somehow, even TS is not running!

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PART 5

If I turn ON TS and I change ONLY CPU core -260 and CPU Cache -130, same behavior, with the difference that PC now is stuck at 3.5 and not 2.7...

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PS

You know what? I see now... before all this problem, with CPU core -260 and CPU Cache -130 I read Max 48-50W is the TS main window
Now, with the same CPU core -260 and CPU Cache -130 (confirmed by CPUID HWMonitor), I have 58.2W Max! That's strange...

Can you help me?



I understand that I MUST avoid to touch TPL parameters. But, I would like to avoid to format again the PC!!!
Can you suggest me what to do? I don't want to format again the PC (and stupid me don't create a windows 10 image).

 

[unclewebb]

Your screenshots show that both the MSR PL1 power limit and the MMIO PL1 power limit are both set to 45W. Your CPU is power limit throttling right at 45W. I am not sure if your laptop supports going beyond 45W long term but if it was my laptop, I would set ThrottleStop up correctly and I would sure try to go higher.

Check the MMIO Lock box, clear the Disable Power Limit Control box and change PL1 from 45W to 60W. Press OK when done and run Cinebench again. Open Limit Reasons and watch for throttling. Exit HWMonitor and the Task Manager. The ThrottleStop data is good stuff. You can trust what it shows.

With ThrottleStop setup properly do you still get PL1 throttling lighting up red under the CORE column of Limit Reasons? If yes, what does ThrottleStop report for power consumption? Is it still being limited to 45W?

It's like TS did something in Windows 10

ThrottleStop does not make any long term changes. If you exit ThrottleStop, delete the ThrottleStop.INI configuration file and shut down your laptop, whey you start back up, the CPU will be set to whatever values the BIOS has set the CPU to. With no INI file present, if you start ThrottleStop, it will read the values that the BIOS has set the CPU to and it will use those values.

I would enable Speed Shift in the TPL window and I would set the Min and Max to the suggested values.

It is usually not a good idea to randomly set the cache to -180 mV. If this has not been properly tested and if it is not 100% stable, you can end up corrupting your Windows install. Usually -130 mV is a good cache offset voltage setting for an 8750H.

 

[scarpinoc]

Hello unclewebb,
mmm... this is what I did... I installed many old versions of TS and play with it. I also run this Windows command:

Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /ScanHealth
Dism /Online /Cleanup-Image /RestoreHealth

Also sfc /scannow


Now, I changed only voltage and I have a very good score for an old 8750h
Almost 3000 in Cinebench R20...
TPL is default and I didn't touch nothing1 and I will never touch it again!
Yes, for what I see, GF75 Thin 8RC can run at 55-60W for short amount of time (max 1 min), then it goes to 4% watt.
But,l with these settings, as you see, I have max 48W consumption during the first 40-45 second, thank to undervolt...

Somthing "magic" happened... Don't task me what! =)

 

[unclewebb]

In the TPL window the turbo power limits are set to 45W long term PL1 and the short term PL2 power limit is set to 90W. This is why you can run beyond 45W for a short period of time. Long term, your screenshots show that you are still PL1 power limit throttling right at 45W. I told you above what you need to do to increase these limits.

I will never touch it again!

There is no reason to be afraid of these limits. They are working normally. The only problem is the power limits are not set correctly.

With the cache offset at -169.9 mV, can you run the TS Bench test? Does it report any errors? If it reports even 1 error, your undervolt is not stable and should be reduced. It is very rare for an 8750H to be 100% stable when the cache undervolt is set to this value. Being Cinebench stable does not mean anything. I too can run Cinebench with very little voltage while other programs or games will crash at the same voltage setting that was good enough for Cinebench.

Your Intel GPU undervolt is not doing anything. You have to undervolt the iGPU Unslice an equal amount or this setting will be ignored.

 

[scarpinoc]

Hello, here a short video of benchmark =) You can open it with VLC.
Do you need more?

https://file.io/ZgitkcDvLOv5

I'm 100% sure that my laptop is locked at 45W. I remember there is a thick model with PL1 65W.

Strange... I rebooted and now I can obtain "only" +-2750 with R20, with the same settings...
Also with Corona Benchmark, I get 2.900.000 Rays/s. Now only 2.650.000... I don't understand =)

But it's ok. PC is stable and with 3.7-3.9 Ghz and good temperature with 75% fan speed.

 

[unclewebb]

The video link did not work. A ThrottleStop log file shows me everything I need to know. You are power limit throttling at 45W long term. The 8750H has a 45W TDP rating so power limit throttling right at 45W is completely normal for many laptops.

Did you check the MMIO Lock box and did you try increasing the MSR PL1 power limit to 60W instead of 45W? ThrottleStop shows that the default power limits are telling your CPU to throttle at 45W long term. Your CPU is doing exactly what you are telling it to do.

Your reduced performance at times likely has nothing to do with your turbo power settings. Windows Defender has a bug that causes this problem. Some computers also change their power limits during a sleep resume cycle.

 

[scarpinoc]

Ohh... I don't know why... and I delete the video. It doesn't matter. Attached is the log.
I also disabled the Windows Defender real time protection and.. you are right, it's a bit better... In Corona, I got 2.800.000 rays/s.

About my laptop, it's bios locked. I remember a discussion on the MSI forum that there is a special combination of keys to enable an hidden bios and change this parameter...
Today I tried to set MSR PL1 power limit to 60W instead of 45W, but wth no luck. my laptop is stuck at 45W after 40-50 seconds. =)

Processor​

MSI has chosen the six-core Intel Core i7-8750H for its thin gamer. This processor can process up to twelve threads simultaneously thanks to hyper threading. The Coffee Lake model has a standard clock rate of 2.2 GHz and can reach 4.1 GHz in turbo mode - although this speed is limited to single-core use like in many other models. When all cores work simultaneously, the i7-8750H can reach a maximum clock rate of 3.9 GHz. The standard TDP is set to 45 watts.

MSI GF75 Thin 8RD (i7-8750H, GTX 1050Ti Max-Q) Laptop Review

A detailed review of the MSI GF75 8RD. The thin and light consumer gaming notebook is equipped with an Intel i7-8750H and a Nvidia GeForce GTX 1050 Ti Max-Q. We will be taking a look at the notebook's features and characteristics including its gaming performance, heat development and noise...

www.notebookcheck.net

 

[unclewebb]

Today I tried to set MSR PL1 power limit to 60W instead of 45W

Did you also check the MMIO Lock box? You need to set the MSR PL1 limit and you need to check the MMIO Lock box.

If you are still limited to 45W long term then you are out of luck.

 

[scarpinoc]

Hi unclewebb,
during the first, I don't know, 40-50 seconds, I reach 48.5 Watt at 3,9Ghz. Then, I go to powerthrottle, at 44.5/45W at 3.75Ghz, with 80% curve fan and 89/90°C.
Even it's possible to change MSR PL1 limit, what's the reason? The PC is stable, good temperature.
And, I'm worried to touch this parameter =)