I5 8250u Power throttling

Hey guys, recently i tried to play Borderlands 2 on Acer Aspire A515-51g but i experience extreme frame drops followed by drops in core speed. CPU never even reaches 80C so temps shouldn't really be the problem. When benchmarking in XTU, it says that it is power throttling, and i can't understand what can i even do about it. I've tried doing stuff in ThrottleStop like raising every limit, but it didn't do anything. There is no TDP control in BIOS settings, but i've seen that in other laptops with the same CPU people have not only higher TDP but were able to modify it themselves (example http://forum.notebookreview.com/thr...tling-on-ac-power-no-matter-what-i-do.814440/). Is it possible in some way to edit the TDP and/or power limit setting on my laptop?

 

What does HWInfo shows for the PL1/PL2.
Also keep in mind that those are not sustained power limit values, after the time(tau) expires the CPU is indeed power limited to 15W.

 

What were the default values for the Turbo Power Limit short and long? Delete throttlestop.ini and restart ThrottleStop if you want to see the defaults.

Also, get rid of XTU (uninstall it) to avoid any potential conflicts. ThrottleStop will provide all possible controls for your CPU at a software level. There is no need to use XTU.

Charles

 

Seems to be 44/15. In the game, i locked the clock to 3100 max so it won't consume over 15w, but the games still run like **** compared to other laptops with the same hardware. Also, got rid if XTU, ty.

 

PP0 current limit set to 0 seems a bit wrong..

 

It got reset after reinstalling throttlestop. Before both PP0 and turbo long/short were maxed out. Didn't really affect performance in any way though. Also, undervolted the CPU by -95. That brought a bit of juice more, but still didn't change much. Any lower and the laptop crashed all the time. And also the GPU is overclocked +200 core and +800 mem. Voltage settings for the GPU are locked though.

 

And is that +800Mhz OC on the GPU RAM stable/really gaining you performance, because RAM OC on GPUs an lead to worse performance due to error correction kicking in and saving your card from crashing but latency goes up like a rocket because the GPU is asking the same data dozens of times..
Run some benchs, to compare to equal GPUs, and also, what is your GPU model?

 

@senso has some good advice.

Suggestions:
--Put back your CPU undervolting settings first. They should be taken into account for everything else you do to the CPU and are very important for keeping temperatures under control.
--In the TPL settings, uncheck the Clamp option. Per the ThrottleStop author it should not be checked as it will cause throttling.

I'd start benchmarking as you change settings to understand what they do. After doing the above, I'd start experimenting with the TPL values; 15W/44W do make sense as defaults. Leave them that way and run TS Bench while watching the Limits window; the CPU power should be at 44W for 28 seconds (which seems like an awfully long time; I'd be surprised if the laptop's heatsink can handle it without thermal throttling) and then drop down to 15W.

If that goes as expected, bump the Long limit up to something like 18W or 20W ...rerun TS Bench and observe the power consumption again.

Start with that approach - changing one thing at a time.

Charles

 

Changing any of the settings did nothing. Cinebench R20, OCCT Linpack, 1024 TS bench didn't push the CPU past 35W and then it always drops down to 15W no matter how much i raise both short and long power limits. Changing turbo time limit also didn't affect anything. Undervolted the CPU didn't even reach 30W, hovering at around 27-28.5. The temps never really go above 70-75 so def no temp limits
The GPU seems to be stable in games, but i'll check the full stability in some benchmarks tomorrow

 

It does sound like something is limiting your CPU. One more good test is to see if the CPU is hitting/maintaining its rated multipliers. In ThrottleStop's FIVR section, you'll see the CPU turbo ratio limits for 1-4 cores active. Use TS Bench to verify the CPU is hitting/maintaining those multipliers.
For instance my Core i7-8565U has 4 cores/8 threads like your Core i5-8250U. So I'd run TS Bench with 8 threads to simulate maximum load (4 cores active) and verify that it's hitting the rated 4-core multiplier during the test. You can do similar testing for 1-3 cores active. Watch the Limits panel while you're doing that, too.

Charles

 

It hits the 3.4gh with 28w, but still goes down to 15w even though the max temp was merely 69C. I was speaking to someone on a different forum, and it seems like i have some power settings in the BIOS, but it's all locked, and write protected. I can get a programmer, but i don't really know what to find the BIOS chip and don't really know how to find and change the settings in it.

 

Its a 15W CPU, you shouldn't expect performance above that because some laptop BIOS are not as locked down and allow longer tau on PL1/2 limits.

 

Well, it was indeed a **** purchase, and you're right that i shouldn't expect anything more, but as i can't return this, i'm looking for ways to increase the performance that is there, inside the laptop, locked by some morons at Acer.

 

Your laptop has a dedicated Nvidia MX150 graphics card, correct?

I am thinking perhaps the CPU power is artificially limited by Acer because the system and/or power adapter may not be able to supply enough power when both the CPU and GPU are running at full-tilt.

Charles

 

Try checking the FIVR - Disable and Lock Turbo Power Limits option. This helps some laptops get over the 15W barrier. Many Acer laptops have set a hard limit of 15W long term which is enforced by the EC. If this is the case, no adjustment in ThrottleStop can be used to get beyond this barrier.

For maximum performance, I would set the Speed Shift EPP variable to 0. You can use a setting of 80 if you need your CPU to slow down when lightly loaded. A setting of 128 on some CPUs can interfere with maximum performance.