# PPo limit reason on i5-5300U and a few other questions



## netsbit (Mar 25, 2022)

Hi everybody, this is my first time posting here so please forgive me if I asked some obvious question haha.

My Dell E7250 is throttling with "PPo" limit reason. I don't know what it is so here is the log file. I can't provide a screenshot because the laptop is running slower than a 10-year-old PC.
Is there a kind of "bible" for adjusting CPU parameters?
I also see people "unlock turbo limits" but mine is locked?
Thanks.


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## unclewebb (Mar 25, 2022)

netsbit said:


> I also see people "unlock turbo limits" but mine is locked?


That is correct. Most older laptops from the 4th and 5th Gen locked a lot of the different power limits in the BIOS. Without a modified bios, which is not likely available, there is nothing you can do to unlock these limits. 





The TPL window shows that the main PP0 Current Limit is locked. Try clearing the check mark in that box on the right side. Reboot your computer, run ThrottleStop, and see if the lock icon on the left side is still there.  

Try checking the MMIO Lock box near the top right of the TPL window. This might help but it will not do anything if the internal PP0 register is also locked.


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## netsbit (Mar 26, 2022)

Thanks for replying, I will report back to you when I have time!

So here is the TPL window after I restart the PC, PP0 current limit is still locked


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## unclewebb (Mar 26, 2022)

Did checking the MMIO Lock box make any difference?


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## netsbit (Mar 26, 2022)

I think it did the trick but I'm not really sure. I will play some games and report back to you


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## unclewebb (Mar 26, 2022)

netsbit said:


> I think it did the trick


The MMIO Lock option locks one of the internal current limits. The main PP0 Current Limit that ThrottleStop gives you access to in the TPL window is already locked so I do not see how that one could randomly start causing a PP0 throttling issue. The MMIO Lock box locks out the secondary current limit so it can no longer be changed. When a register like this is locked, you have to reboot to unlock it. Doing a sleep resume cycle could unlock it. If you leave ThrottleStop running in the background, both current limits will remain locked. 

Hopefully this fixes your PP0 throttling problem.


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