# different cinebench scores on an i7-8750H (dell xps 15 9570) & several throttlestop setup questions



## theraseus (May 8, 2022)

Hi guys, 

I have a cursed dell XPS 15 5970 with an  i7-8750H.  I use it mostly for graphic design ( adobe package) and cinema4d and octane.

I have run several tests using cinema bench as the title says, and even without changing any settings in throttle stop, I get very different results. ( i am attaching a few screenshots and logs, not sure if the logs are the right way) the info not present in the screenshots is my voltage offsets

Cpu core: -202
Icc max: 255
Cpu cache: -140
Icc max: 255
Intel cpu: -125
Ipu slice: -125

Today my first cinema bench run (after the laptop was off for several days) yielded the best results yet: a score of *2839,* but later it dropped to* 2600. *and then the latest test I did was a score of* 2300.*

I notice the issue is a VR THERMAL warning across the core, GPU, and ring. when that happens my processor goes from a steady 3.500 MHz to 2.000 MHz.  this, I believe, is caused by power throttling.

* I have a few questions:*

1) I have disabled the intel DPTF using what is advised in this link https://bradshacks.com/disable-dptf/. *should i still be having VR THERMAL warnings after doing so?*

2) during cinebench ( no matter the score I get) my temps stay up around 89-90 and they go up to 98 occasionally. ( i have done a few dozen tests and it never goes beyond that)
*
is this safe for my laptop? should I maybe enforce a lower clock speed to ensure lower temps ( i have to work for long periods of time using both the gpu and cpu when doing 3D animation and work)*

3) *I am not really sure how to set up settings into TPL*, I have mostly been trying out different settings and comparing results, but i don't really understand what I am tampering with, and how it is affecting everything. any help on that area would be really appreciated.

4) I have changed my thermal paste and added some padding to my laptop according to this guide. m*y idle temps oscillate between 35 in the best scenario to 45-50. which I think is pretty good. but I still get to really high temps during load. is this normal?*

5) after clicking on the first checkbox in throttle stop and setting it to high performance, no matter what I do the clock is always running at full speed, I read before that this is related to the power mode you select in battery settings.i and that it is recommended to have it in balance or power saver, so when you are at idle your laptop is not running at full speed unnecessarily. now I can't really revert this back to that self-adjusting behavior. is this a bug?

i have been trying to optimize this laptop for a long time, any help would be greatly appreciated, thank guys!









Toda


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## X71200 (May 8, 2022)

Cinebench goes all on out on SSE instructions and heats up the CPU quite a bit. In this case, it's kind of cooking your laptop and temp throttling. You can use Throttlestop and adjust a better profile regarding your 3D work. However, this is not a machine meant for this kind of work so... it'll overheat.


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## unclewebb (May 9, 2022)

theraseus said:


> the issue is a VR THERMAL


VR THERMAL means the voltage regulators are overheating and causing throttling. Your laptop might be the model where Dell did not put any sort of heatsink on the voltage regulators and there is not enough air flow so inevitably they overheat. This type of throttling is more severe compared to power limit throttling so you might be better off reducing your turbo power limits to try to avoid the voltage regulators from overheating.

You have to make a choice. Do you want great performance to be followed by severe throttling or do you prefer consistent but somewhat mediocre performance? Maybe Dell needs to include that question on their sales sheet for XPS laptops.

The 8750H has a 45W TDP rating. Dell has a feature that will lock the long term turbo power limit to 45W. This limit is separate from any limit that ThrottleStop lets you set so no use trying to fight it because you cannot.

I usually avoid undervolting the Intel GPU or iGPU Unslice. If you have a Nvidia GPU for playing games on then the Intel GPU is not usually loaded significantly so undervolting it can cause instability without accomplishing anything. If you are stable when undervolting these two then you can leave it as is.

If your core and cache offset voltage settings are 100% stable then you can leave those as is too. There is next to nothing to be gained by trying to go further and you will definitely run into stability issues very soon. Can you run the TS Bench without it reporting any errors? If errors are reported or you get the occasional blue screen crash, try reducing the cache offset voltage to -130 mV or -125 mV.

Setting the power limits more conservatively to about 45W to 50W for PL1 and 60W for PL2 is probably more realistic compared to setting the power limits higher and having the voltage regulators overheat. The turbo time limit should be somewhere around 16 seconds or less. Running your CPU at the 60W PL2 limit for much more than 16 seconds might trigger severe throttling.



theraseus said:


> should i still be having VR THERMAL warnings after doing so?


Yes. VR THERMAL throttling and Brad Hacks suggestion that you disable the PL2 power limit or the DPTF hack have nothing to do with each other. The only way to solve VR throttling is to improve the cooling of the voltage regulators.



theraseus said:


> they go up to 98 occasionally. ( i have done a few dozen tests and it never goes beyond that)


Dell has set the thermal throttling temperature to 97°C. The CPU will slow down as much as necessary so it will rarely exceed 97°C. That is how thermal throttling works. The temperature sensors that Intel uses also stop reporting data at 100°C so you will never see a temperature number higher than that even if you put your laptop in the oven.



theraseus said:


> is this safe for my laptop?


No one in any forum can guarantee how safe your laptop will be or how many years it will run for if you decide to constantly run it at 95°C or beyond. Intel says that any temperature under 100°C is a safe operating temperature for their CPUs. No one knows about the components near your CPU that might or might not be able to handle those sort of temperatures long term. The XPS line is hardly over designed.



theraseus said:


> really high temps during load. is this normal?


Yes. This is normal when manufacturers install 6 core CPUs in a confined space and then use barely adequate cooling. Poor laptop design like this is everywhere. Dell is not the only company that thinks this is OK. This can make it difficult or impossible to run the CPU at its full rated speed. If you set both of the turbo power limits to 45W and run the CPU at the Intel spec then it might be able to manage that without overheating.



theraseus said:


> and setting it to high performance, no matter what I do the clock is always running at full speed


That is the purpose of the Windows High Performance power plan. It tries to run the CPU at full speed regardless of load. This power plan usually sets Speed Shift EPP to a value of 0. Clear the Speed Shift EPP box on the main screen of ThrottleStop and try letting Windows manage the EPP value. With this box clear, use ThrottleStop to switch to different power plans and look in the FIVR monitoring table to see what EPP value the CPU is using. The Balanced power plan typically sets EPP to 84 and on my desktop computer, the Power Saver power plan sets EPP to 153. These power plans allow the CPU to slow down when it is lightly loaded. If Windows can manage this setting, you do not need to check the Speed Shift EPP box on the main screen of ThrottleStop.



theraseus said:


> is this a bug?


No, this is because you decided to check the Speed Shift EPP box and you decided to set the EPP request value to 0. This is how to request maximum speed regardless of load and the CPU is delivering exactly what you are asking for.



theraseus said:


> optimize this laptop


The only optimization you can really do is lower the power limits and de-tune your laptop. The cooling is not adequate to run your laptop indefinitely at its full rated speed so some power limit throttling is a necessity to avoid the VR voltage regulator thermal issues.

Edit - I would check the MMIO Lock box. If you check this box, you do not need to check the Sync MMIO box. I prefer to check the Short Power PL2 box. I like setting Power Limit 4 to a value of 0 which tells the CPU to ignore this limit. I also clear the BD PROCHOT box.


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## theraseus (May 9, 2022)

hi @unclewebb, thanks so much for taking the time to explain things to me! i really appreciate how you always reply to eveyone!

i did the changes you proposed , this is how my  TPL window looks now, is this correct?






i got some interesting results:

disabling speed shift EPP and letting windows handle it did  let me choose between the different power plans, it is working exacly as you said.

I did a few tests, selecting high performance ( Speed shift EPP of 0) and balanced (speed shift of 128) and in both cases my clock was running at 3200 mhz constantly. 

*Balanced*

i got no sort of warning on my limits \ throttle  when using the balanced option. and my temps didnt raise over 75 degrees. i got a 2450 score on cinemabench.

*high performance*

i got the same results on cimemabench, and myclock speed was the same (3200 mhz), but i did got higher temperatures (around 84) and some limits ( see image below)





i dont rreally understand, considering the high performance profile has a Speed shift of 0, i understand getting higher temps and limit warnings . but shouldnt the clock be working higher than 3200 mhz?

and considering that on the balance profile i got to a speed of 32.000 mhz at 74 degrees max temp. 

should i try to tweak it a bit more and see how far i can go without trottle? maybe changing the speed shift value from 128 to a slightly different one? what do you recommend?

Thank you!


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## unclewebb (May 9, 2022)

theraseus said:


> shouldnt the clock be working higher than 3200 mhz?


When PL1 or PL2 power limit throttling is lighting up red, the CPU speed is being reduced so it does not exceed the turbo power limits. Whether you are using the Balanced or High Performance power plan will not make any difference if the CPU is power limit throttling.



theraseus said:


> should i try to tweak it a bit more and see how far i can go


That is a good idea. You want to run as fast as possible without overheating the voltage regulators. If increasing the turbo power limits overheats your voltage regulators and your CPU throttles down to 2200 MHz, that would not be good. You should never see VR THERMAL lighting up red in Limit Reasons and you should never see VRTEMP in the far right column of the log file.

Some PL1 or PL2 power limit throttling is OK. It is the VR throttling that you need to avoid. Settings that work OK on a cold day inside your house might cause VR throttling on a hot summer day. That is why I would not spend too much time trying to come up with some sort of perfect setting. Leave some headroom so you do not have to constantly test and adjust your settings every time the sun comes out from behind a cloud. 

When you are living on the edge of throttling, do not expect to see consistent performance from one run to the next. There is only so much turbo boost available. If you run a Cinebench test twice in a row, it is normal to get more turbo boost and higher MHz the first time you run a test compared to the second time you run the same test.

I would check the Speed Shift box in the TPL window and I would set Speed Shift Min and Speed Shift Max to the suggested values, 8 for Min and 41 for Max. This just makes sure that these values are properly maintained.


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## theraseus (May 10, 2022)

hi @unclewebb,

Thanks a lot for the tips, this setup seems to be working fine, havent seen any VR throttling  (VR THERMAL or VER TEMP).  I will test setting speed shift to 0 for min and 41 for max and see how it goes after using cinema4d and octane and see if everything is stable.


i have a last doubt regarding C0%: all of my cores seem to be working at different C states, sometimes a few of them spike more than the others. is this expected? or it may be a bad thermal paste job on my end?





Thanks!


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## unclewebb (May 10, 2022)

theraseus said:


> is this expected?


Yes, it is completely normal. 

When a CPU is not fully loaded, every core and every thread will spend a different amount of time in the C0 state. When cores and threads are not actively working on a task, they enter one of the low power C states like C1, C3, C6 and C7. The amount of time each core and each thread spends in any C state is as random as random can be. 



theraseus said:


> I will test setting speed shift to 0 for min and 41 for max


ThrottleStop does not allow you to set Speed Shift Min to any value less than the minimum which for an 8750H is 8.


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