After using ThrottleStop, post restart is locked to 800 MHz (0,8 GHz)

My computer is MacBook Pro 16" (2019). I don't know what role that has in this problem. This is what happens:

I need to use ThrottleStop because this laptop runs way too noisy (fans) and hot with default throttle. The max multiplier is 48T (4800 MHz) but after countless tests I have gathered that 30T is the sweet spot (reasonable CPU temps but max average CPU speed while reducing the heat). And to be more precise, the settings are: [x] Set Multiplier 30T, [x] Speed Shift, [x] SpeedStep, [x] C1E.

After a restart, booting to either Windows 10 or macOS, the clock is locked at 800 MHz. So it boots extremely slowly. I do not know any way how to fix that. However, as soon as ThrottleStop is loaded, it gets the CPU settings from there and clock is fast again (e.g. 3000 MHz).

Mac computers have the SMC reset trick (has to be done during booting) and that also fixes the problem temporarily. But as soon as something happens (I think something related to ThrottleStop), the CPU is locked at 800 MHz again. macOS is completely useless at that point (almost stopped, so slow).

Does someone know what happens here and where is the 800 MHz state saved?

Is there some way to prevent this? The ThrottleStop setting [x] BD PROCHOT is quite suspicious for this, because turning it on also causes the 800 MHz lock. However I don't use that and it still goes to similar state on reboot (I also noticed that sometimes the computer survives two reboots without suffering the problem, but eventually the problem always appears).

 

@jihoy - Speed Shift and SpeedStep are two different things. SpeedStep and the Set Multiplier variable can control your CPU speed or the Speed Shift settings can control your CPU speed. They do not both control your CPU speed at the same time. I am not sure what settings a MacBook uses.

If checking the BD PROCHOT box in ThrottleStop forces your CPU to 800 MHz then that is your main problem. There is a 1200 page ThrottleStop forum on Notebook Review. The link to this forum is in my signature.

Search the ThrottleStop Forum for BD PROCHOT and enter my user name into the search box. This is the best way to learn about ThrottleStop.



Open up Limit Reasons. Does it show BD PROCHOT throttling when your computer is stuck at 800 MHz?



BD PROCHOT is a signal path to your CPU. Any sensor within your computer can send a throttling signal down this line directly to your CPU. This will force the CPU to 800 MHz. When you clear the BD PROCHOT box in ThrottleStop, this tells the CPU to ignore any external throttling messages. Your CPU will still thermal throttle if it ever gets too hot whether BD PROCHOT is checked or not.

Head to the ThrottleStop forum and post lots of pictures so I can see how you have ThrottleStop setup. It is hard to help you when you do not provide any information.

 

Thank you so much, I feel like this is about to get sorted now that I found you! Your answer is completely in line with what I felt was going on without finding much of documentation.

Quick comments to your questions: yes BD PROCHOT is red in Limit Reasons when the computer is stuck at 800 MHz. I also use Macs Fan Control but I didn't see any difference in regards to this BD PROCHOT situation whether using that or not.

Just by intuition, I suspect that my MacBook senses too high temperature (possibly also too slow fans) and then creates this throttling signal you mention. And SMC reset clears that throttling signal. Do you know whether there is any other way to clear this throttling signal (so that it would be cleared at reboot)?

 

I am not familiar with Apple computers. The throttling problem you are having might not have anything to do with temperatures. Any sensor can short out or go bad. If it completely fails, the sensor might permanently send a throttling signal to the CPU via the BD PROCHOT signal path. This is a fairly common issue with a wide variety of Windows PCs, both laptops and desktop computers. It is rarely diagnosed correctly. Beyond ThrottleStop, no other software I know of reports BD PROCHOT throttling and no other software besides ThrottleStop gives you any option to disable the BD PROCHOT signal path.

I have no idea if it is possible in a Mac to tell the CPU to ignore these messages when it is booting up. My best guess would be, probably not possible. You are going to have to live with slow and sluggish boot times if the CPU is stuck at 800 MHz.

In many Dell laptops, this kind of throttling signal can be generated by the power adapter. If you have access to a spare, try using that to see if it makes any difference.

 

I found a few similar stories in <10mins of googling. Did you try searching on apple tech forums?

Many anecdotes pop up of 800Mhz speeds due to what are ultimately chipset/driver issues, when using bootcamp.

If the SMP and PRAM resets didn't work, and you have verified that power source isn't an issue, then it looks a lot like some of these:

https://discussions.apple.com/thread/7582197

https://discussions.apple.com/thread/250549591

Also, it would be a good idea to run tests with/without the "Macs Fan Control" program to check what (if any) impact that is having. Mac throttling+fans is closely linked and infamously problematic and there's surely an extra layer of complication going on between the interplay of Windows OS, Mac OS, Intel drivers, Macs Fan Control, and TS, so reducing the variables as much as possible to figure out what's happening is recommended.

Either way, something is redundant and useless if you're using Macs Fan Control already but then also "need to use ThrottleStop because this laptop runs way too noisy (fans) and hot with default throttle". If this is the case, then you might want to consider backing up and checking with Apple support about the underlying issue in the first place. Of course, the truth of that answer will simply be that the cooling solution is inadequate for the hardware, but there also might be a flaw or critical error with some of your hardware, or again, most likely, some issue in the interaction between windows OS, mac os, and chipset, any of are plagued by bugs that often appear in situations like this)

I'm certain that you're mistaken about the throttling being related to or caused by TS. Nothing about the flag being detected (or clearing it) is suspicious; rather, the opposite: TS allowing to clear the flag is likely to be the solution for "un-throttling" once it already throttled. At least, that was the case in some threads such as the one linked above.

Good luck, I'd suggest researching/asking advice on mac-centric sites, as this seems to be a fairly common problem that appears year after year so I'm sure you can find some relevant advice/tips. I wasn't able to get more helpful query results without knowing your OS versions, but it seems like there's plenty of bugs or discrepancies to be found when throttling running bootcamp and sensors are detecting different readings under different OS environments, so combined with Mac throttling scheme in the first place, you may need to narrow down the variables a little more to solve this.

 

Thank you for the responses. This is all complicated and extremely slow to test. One thing I did find out. I do not know what the explanation is, but once the 800 MHz lock is set, I think on each reboot the system will be at 800 MHz, booting for both Windows 10 and macOS. And if I boot only to Windows, it'll indeed be 800 MHz until ThrottleStop has loaded. However, I once spent a longer while in macOS, while in 800 MHz, and suddenly the 800 MHz was unlocked to full throttle. I didn't do anything. I'm not sure what happened, but I didn't load any programs or change any settings.

Then, I booted to Windows and there also the 800 MHz lock was gone.

In other words, if the lock appears, I can get rid of it with a SMC reset, but also apparently by just sitting on macOS for 15+ mins without doing anything (special).

I'll write again if I get some more sense to this. Meanwhile, if someone can explain what might've possibly removed the 800 MHz spontaneously..