Lenovo Y540 I7-9750h CPU undervolt

[ABSousa]

Hi, I got a Lenovo Legion Y540 I7-9750h, rtx2060, 16gb ram recently and I've been testing around with Throttlestop since it gets so damn hot from stock (I'm new at this).

I was following a guide that says that we should leave the Cache undervolt at -.125 and just test around with the Core to the max possible. 
Today I went to try and mess with the Cache a bit and went up to -.200 where it gave me a blue screen in idle, no problems with the benchmarks, after that I tuned down to -.175 in Throttlestop that actually shows up in HWmonitor as .-180 and so far so good.

At the moment I have a -.300mv on Core and -.180 on cache but I've read around that intel takes on the same for both so I guess I'm at -.180?
I've ran cinebench r20 a few times getting 3100-3120 score range.

I've also attatched a screen of my current configuration. The throttling shown in the stress test is right when I start it since the fans are not at max power.

TL;DR If you guys can take a look at my config and tell me if I'm messing up in some point I would appreciate it.

Thanks!

[unclewebb]

Your settings look good.  When testing, why not open up ThrottleStop Limit Reasons.  If you see a box glowing in red, that will tell you the reason why your CPU is throttling.  It looks like you have one of the turbo power limits set to 70 Watts and that is why your CPU is throttling.  Post a picture of how you have the Turbo Power Limits window setup.

 

I would check the FIVR - Disable and Lock Turbo Power Limits option.  When using this option, first you will need to click on the Install button.  Follow the directions.  Download and install the RwDrv.sys file into your ThrottleStop folder before selecting this option.

 

There is a lot of debate about whether reducing the core offset lower than the cache offset does any good or not.  This might depend on the test you are running and whether it is using any AVX instructions.  If you do not see any advantage during testing then there is no reason to set these offsets differently.  Just because lots of other people are doing this does not mean it is right.  Lots of people follow along without doing any testing.  If you do see an advantage then obviously you should continue doing this.  I have asked lots of people to show an example to prove this one way or the other but no one ever bothers.  An A-B-A test involves making a change, checking for an improvement and then going back to the original settings to see if you can confirm that there really was an improvement in temperatures or performance.  Consistent results when testing on a laptop are not easy to get.

 

ThrottleStop does not have access to the full Intel documentation so it is possible that a setting of -0.175 mV in ThrottleStop is actually -0.180 mV.  Here is the math.

  

Is 180 / 1000 (0.180) correct or is TS correct when it shows 180 / 1024 (0.175).  Most computers are based on powers of 2 so using 1024 for the divisor might be right.  It is not worth arguing or worrying about this small of a difference.  Use whatever offset setting that you can run your CPU at reliably.

 

Lenovo has set the thermal throttling temperature (PROCHOT - Processor Hot) on your laptop to 94°C.  This is well below the 100°C spec that Intel recommends so no worries about hurting your CPU.  It will thermal throttle and slow down well before it ever gets too hot.

 

Running over 3100 in Cinebench R20 is great.  Read a few random reviews. 

 

https://www.techspot.com/review/1847-intel-core-i7-9750h-vs-8750h/

 

Good luck finding a 9750H at default specs running as good as your CPU is running.  Your TS tweaks have made a significant difference.  See if you can change your title.  You have a Core i7-9750H, not a Core i7-7950H.  A brief moment of dyslexia!

[ABSousa]

Thanks for the super detailed reply!

I did as you said and tested again with the previous configuration to check the Limit Reasons with the 70 power limit and after doing what you suggested I got rid of the red throttle warnings but got a thermal yellow.

Managed to get 3149 in the benchmark as well with this change.

[unclewebb]

Limit Reasons makes it easy to figure out what is going on when testing.  PL1 is equivalent to the Turbo Boost Long Power Max value which is set to 70.  If the CPU tries to exceed 70 Watts, it will automatically slow down just enough to prevent it from exceeding this value.  It is common for the RING - EDP OTHER to light up at the exact same time as PL1.  It is definitely PL1 that is the cause of throttling.  As you found out, raising this power limit will make power limit throttling go away.  You can also click on the headings in Limit Reasons to clear this information out of the CPU.  Good idea to do this before you start testing so you have a clean slate.

 

Now if you can find a way to keep your CPU cooler, it will not thermal throttle so your Cinebench scores might go up a little more.  3149 in Cinebench R20 is excellent.  Most apps / games are not going to work your CPU this hard.  You can either leave the long term power limit set to 70 Watts and let power limit throttling take care of things or bump it up to 75 Watts or 80 Watts and let thermal throttling take care of things.  Intel CPUs have lots of technology built into them so they do a great job of looking after themselves.

 

Nice to see that Lenovo has left the power limits unlocked so they can be adjusted with software to prevent throttling.  Many Dell and Asus laptops will lock these limits in the bios so it is impossible to achieve maximum performance.

 

Did you try to prove yet if setting the offset voltages differently actually works?

[ABSousa]

I just did it and seems there is an obvious difference. I was trying some configurations and I guess I'll go for the -70 Watts for now, but it's nice to know where to get a little extra juice if I ever need it. Had to up my undervolt on cache from -.180 to -.175 since I got a blue screen (Two Point Hospital seems to be a great stress test for this).

Results with 75w -.300mv core -.175 cache 

 

Results with 70 Watts -.300 core and -.175 cache

 

 

After picking the 70 Watts setup I went and changed the Core to -.175 and the cache at -.175 and got a decent decrease of performance 

 

Just realized I forgot to take a screen of the AIDA test with this last config but It had a lower CPU boost speed.
 

[vishal_adi]

Hey @ABSousa just wondering if lenovo will void my warranty if i undervolt my CPU.

I recently got the same config as you and man oh man the struggle is real when it has to render..

I do a bit of heavy architectural design work and when I render using VRay or anything, my laptop noticably thermal throttles and i heard that undervolting helps so I'm sorta looking to do it to have my workflow be smoother and faster (and cooler) but at the same time it's also my daily driver so i don't want to ruin it in any way (including but not limited to warranties and bricking my device) so i was hoping you could give me some clarity about this warranty voiding and the how to undervolt and stuff 'cause I'm a total noob (sorry).

Thanks in advance.

[ABSousa]

On 10/12/2019 at 7:56 PM, vishal_adi said:

Hey @ABSousa just wondering if lenovo will void my warranty if i undervolt my CPU.

I recently got the same config as you and man oh man the struggle is real when it has to render..

I do a bit of heavy architectural design work and when I render using VRay or anything, my laptop noticably thermal throttles and i heard that undervolting helps so I'm sorta looking to do it to have my workflow be smoother and faster (and cooler) but at the same time it's also my daily driver so i don't want to ruin it in any way (including but not limited to warranties and bricking my device) so i was hoping you could give me some clarity about this warranty voiding and the how to undervolt and stuff 'cause I'm a total noob (sorry).

Thanks in advance.

Sorry for the delay, in fact my motherboard had some problems in the GPU part so I had it sent to service, and they ended up swaping the entire board, I'm now testing with the new chip to see where I can get the sweet spot.

As far as I know you are just taking power from your cpu to avoid the overheat and the thermal throttle that comes with it, for what I read around it is quite safe and won't void warranty. Altho you are taking away power from it your are getting perfomance since you avoid the big cut of thermal throttle.

Also you can check this guides, takes like 20min for both but you get a ton of information about the process:

 

I'm also a noob in this area but you can see the huge improvement, you can go from scoring 2600 in cinebench r20 to 3000-3100 just by avoiding that massive thermal throttle.

Goodluck with your unit ^^

PS: Remember that every unit is different, so don't use the values I used right away!

[iSjaak]

Hi,

 

I have the same laptop as you and I've been experimenting a bit with Throttlestop. The undervolting part I understand. In your TPL window though, I can see that  your Turbo Boost Long Power Max is set to 70 and your PP0 Current Limit is set to 130. As far as I understand, these values concern the maximum Wattage that the CPU is allowed for long and short term Turbo use. Mine are set far lower, 60 and 80 respectively. If I increase these values, I can see the Wattage increase in HWMonitor. Naturally the temperature increases as well, but doesn't get over 90. So what I was wondering: can somebody explain to me exactly what these values govern and can I increase those values safely as long as the temperature remains under control?

 

Thanks in advance.

[alen29]

Hi @ABSousa.

 

Can you please explain how you solved the CPU throttling down? I also have PL1 set to 75W and PL2 to 107W, but the CPU after some time automatically decreases the power limit and doesn't go over 60W no matter what I do.

What BIOS version do you have? Mine is version 26.

[unclewebb]

@alen29- Make sure you are using the ThrottleStop FIVR Disable and Lock Turbo Power Limits feature. This helps take care of the secondary set of power limits. Try running Cinebench with Limit Reasons open to check for throttling.

[cocheez]

On 9/19/2019 at 4:53 PM, ABSousa said:

The throttling shown in the stress test is right when I start it since the fans are not at max power.
 

Is there a way to stop this from happening without a dedicated max fan option? By undervolting I've managed to stop throttling when my laptop is at full load and the fans are going but still get the throttling when I first start the stress test.

[gorilazxz]

On 9/20/2019 at 12:53 AM, ABSousa said:

Hi, I got a Lenovo Legion Y540 I7-9750h, rtx2060, 16gb ram recently and I've been testing around with Throttlestop since it gets so damn hot from stock (I'm new at this).

I was following a guide that says that we should leave the Cache undervolt at -.125 and just test around with the Core to the max possible. 
Today I went to try and mess with the Cache a bit and went up to -.200 where it gave me a blue screen in idle, no problems with the benchmarks, after that I tuned down to -.175 in Throttlestop that actually shows up in HWmonitor as .-180 and so far so good.

At the moment I have a -.300mv on Core and -.180 on cache but I've read around that intel takes on the same for both so I guess I'm at -.180?
I've ran cinebench r20 a few times getting 3100-3120 score range.

I've also attatched a screen of my current configuration. The throttling shown in the stress test is right when I start it since the fans are not at max power.

TL;DR If you guys can take a look at my config and tell me if I'm messing up in some point I would appreciate it.

Thanks!

Hy ABSousa.please tell me your config   that u made on lenovo y540  with throttlestop .I have the same config on my lenovo y540  intel core i7 9750H with RTX 2060 .my thermal cpu is on  fire and i dont no what to do...i will leave my email if u please  share u re config that u made to undervolting with throttlestop .I will be much apreciatte.mariusadrian666@gmail.com. my email.Thank u so much.