i7-8550u TDP capped at 15 Watt, any possible solution?

[davejs4]

I have a laptop, acer swift 3 with i7-8550u
Whenever I use throttlestop, it will boost my performance for a maximum of 5-10 seconds with TDP of 25 before the TDP goes back to 15 watt. This happens numerous times.

Things that I have tried:
1. Changing value of Turbo Boost Long Power Max and Short, I changed it from anything over 15 to 35 but it doesn't matter as it will only last for around 5-10 seconds before going back to 15 W.
2. Changing TDP level control value from regedit in Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\48df9d60-4f68-11dc-8314-0800200c9a66\07029cd8-4664-4698-95d8-43b2e9666596
3. Uninstalling Intel(R) Dynamic Platform and Thermal Framework .. in device manager

I included pictures of
1. when my throttle stop first activated to use for Cinebench
2. After the TDP is down powered to 15 W
3. My limit of red EDP other and PL1 with yellow PL2 which shows that this is not a thermal problem (not even close)
4. My FIVR settings
5. My TPL settings
6. My specs information when throttlestop is on according to HWiNFO

Supposedly, my CPU should have low TDP of 10W with highs of 25W but the limit is always stuck at 15 watt no matter what I do. This shouldn't have been a thermal problem as I have previously run on it with temps of >85 degree celsius with no problems. I suspect that Acer might put a power limit of 15W on my laptop but I'm not entirely sure. It's just annoying when you could have boosted your performance by a lot with no drawbacks but the company puts a stupid limiter on it. Which is stupid since my laptop cooler should be able to perfectly handle enough heat from the little turbo boost to 20-25 watt.
I also attached a log file of my throttlestop performance when undergoing Cinebench at the bottom.
Any help and suggestions would be greatly appreciated.

 

[repman244]

Whenever I use throttlestop, it will boost my performance for a maximum of 5-10 seconds with TDP of 25 before the TDP goes back to 15 watt. This happens numerous times.

It probably starts thermal throttling after that. It's a thin laptop with limited cooling you can't expect to run 25W or even 45W CPUs in that thing. It also depends if you are loading a single core or all of them.

 

[joemama]

This shouldn't have been a thermal problem as I have previously run on it with temps of >85 degree celsius with no problems.

Do you mean you haven't observed throttling at >85 degrees celsius before?
Because 85 degrees should be a temperature high enough for the laptop to start throttling, also I don't know if it starts throttling gradually before reaching 85 degrees.

 

[davejs4]

Do you mean you haven't observed throttling at >85 degrees celsius before?
Because 85 degrees should be a temperature high enough for the laptop to start throttling, also I don't know if it starts throttling gradually before reaching 85 degrees.

Yeah I mean I have already used it before with around 85+ degrees celcius when my cooling was bad. So I decided to clean out the dust in the fan and put some thermal paste for the cpu thinking thermal was the original problem. After that, my normal temp dropped by 10-20 degrees, but my laptop wouldn't stop throttling eventhough it has much lower temprature than before. Before, it was 50 degree idle with 85+ degree for extensive test but now it's 35 degree idle with 65+ for extensive task.

So apparently even after having much better cooler, my power would throttle at the exact same spot at 15 watt. It wouldn't make sense for it to be a thermal problem since the problem still exists even after a huge temperature drop. At that time, my limit of thermal would be yellow and PL1 would be red.

After the changes, my thermal is no longer yellow but pl1 still remains red which led me to believe that it's not a thermal problem anymore. It's always locked at 15 Watt even if the temperature mostly never exceed 70 degrees. It's usually around 66-68 degree which shouldn't have been a problem.

In summary, if it previously throttles at 85+ degrees, why is it now still throttling at 65+ degrees even after getting a better cooler. It wouldn't make sense to be a thermal problem if you ask me.

 

[repman244]

Did you check bios settings for configurable TDP or similar?

 

[Caring1]

I'd say the 15W is set by the manufacturer which gives them a safety margin and allows cheaper cooling components to be used reducing their costs.
Quick question, what capacity power brick are you using?

 

[davejs4]

Did you check bios settings for configurable TDP or similar?

nope, I already checked the BIOS but no such things

I'd say the 15W is set by the manufacturer which gives them a safety margin and allows cheaper cooling components to be used reducing their costs.
Quick question, what capacity power brick are you using?

you mean the charger? It's a 65W with small pin. Yeah I suspect that the manufacture might put a limit on the power output. Is there no way to get around it?

 

[unclewebb]

I suspect that Acer might put a power limit of 15W on my laptop

That is correct. There are 3 sets of turbo power limits. The CPU compares these 3 different sets of power limits and always uses the lowest one. ThrottleStop and Intel XTU only have access to 2 of these sets of power limits. The third set is controlled internally by the EC. Some manufacturers do not use the third set of turbo power limits. On your laptop, Acer is forcing a 15W long term turbo power limit which is equal to the rated TDP.

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ark.intel.com

Your Limit Reasons screenshot confirms that this is a power limit throttling problem. Nothing to do with temperatures. It is not thermal throttling.

You are also correct that these CPUs can perform WAY better when manufacturers do not enforce a 15W power limit. I have a Lenovo C930 with the same 8550U but this laptop does not use the third power limit. Big difference.

http://imgur.com/eo0J744

The only thing holding it back is a heatsink that was never intended to be used at this sustained power level. With proper cooling and unlocked power limits, the CPU is more than capable of running at its full rated speed indefinitely.

 

[yotano211]

Try undervolting the processor

 

[unclewebb]

Try undervolting the processor

The 4th screenshot that @davejs4 posted shows that he is already undervolting the CPU.

 

[snydelol]

@davejs4 hi, did you manage to find a fix to this? I am currently facing the exact same issue on my HP laptop.