Look at your first screenshot. The cores are equally loaded running Cinebench but the temperatures of the first four cores vary; 97°C, 80°C, 100°C, 79°C. This is always a sign that the heatsink is not making even contact with the CPU cores. It might be a problem with the thermal paste or thermal pad or it might be a heatsink that is not perfectly flat like it needs to be to make proper contact. I have zero Apple experience so I am not sure if this is normal or not. The heatsink on the CPU needs to be removed and inspected for flatness with a straight edge and the thermal paste needs to be replaced. I have heard that Noctua NT-H2 works well at high temperatures. You need a top quality paste to survive at 100°C without it pumping out.
If you installed the RW driver into the ThrottleStop folder, you can remove it. The newer versions of ThrottleStop no longer use this driver.
I only check the "disable and lock turbo power limits", which seems doesn't work.
It looks like it is working. Why do you think that it is not working? If your CPU is grossly overheating, checking this box is not not going to solve your overheating problem. The 9880H has a 45W TDP rating. Your cooling cannot prevent the CPU from overheating and thermal throttling at only 35W. That is the problem.
And IMHO, the pl2 shouldn't be there
Only worry about boxes lighting up red under the CORE column in Limit Reasons. The first screenshot shows THERMAL glowing red. That is the #1 problem that is causing throttling. Some Apple laptops have a poor reputation for including proper cooling. With an inadequate heatsink, it is normal for some Apple laptops to continuously bounce off of the thermal throttling temperature when trying to perform any stressful task like running Cinebench. Hopefully the heatsink is adequate to fully handle the heat a 9880H can put out. This CPU probably needs over 70W of cooling so it can run Cinebench at full speed. Your cooler is struggling at 35W. Without proper cooling, your 9880H will only run Cinebench at about 60% of its maximum rated speed.
quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.
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The 9880H does have a Configurable TDP-down capability of 35W. Most PCs do not use this low TDP mode. I am not sure if Apple uses this. Fix the cooling first and you can worry about everything else after that.
TVB throttling can be solved by clearing the Thermal Velocity Boost box in the FIVR window. Unfortunately your laptop has locked the FIVR voltage control register so you have to live with some TVB throttling.
Watch for VR CURRENT turning red in Limit Reasons. This means the on board voltage regulators might not be designed to provide enough current to fully power a 9880H CPU. It takes a lot of engineering to get maximum performance out of an Intel 8 core mobile CPU. Installing a 9880H into a poorly cooled, thin and light laptop with inadequate voltage regulators is not going to cut it.
