Undervolting help requested for Lenovo Legion Y740-15IRHG

[LoneWolf~]

I bought this laptop recently for a great price and overall it keeps impressing me. Lately it was when I bought sticks of DDR4 3200 RAM and saw that it ran at that speed with an XMP profile despite reading elsewhere that it wouldn't go beyond 2666. I've undervolted laptops in the past to reduce thermals and limit throttling mostly with Throttlestop but ran into problems this time.

After reading around I saw that it was disabled in a later BIOS but most of the options in Throttlestop were available to me. However, despite changing the CPU and CPU cache to -125mV, saving the profile and applying it the voltage didn't change at all. Normally I see the change reflected in the top right box under the FIVR tweaks but nothing happened. I've even gone so far as going back to 1.08 in the BIOS which didn't change this as well as looking to edit the BIOS itself which showed that the overclocking lock was disabled.

I have no idea what to check or change now and I'm no nearer to getting it to work. If anyone has suggestions or knows what I need to do I'd welcome the help. The attached screenshots are from the laptop while typing this post out and sitting on a cooling pad otherwise the temps would be higher.

 

[unclewebb]

ThrottleStop voltage control does not work when Windows VBS is enabled. Follow the link in my signature. Core isolation memory integrity needs to be disabled and anything else that depends on virtualization also needs to be disabled.

After you do that, reboot and delete the ThrottleStop.INI configuration file before running ThrottleStop. Post an updated FIVR screenshot. You should not be seeing a column of 0.3799 values in the ThrottleStop FIVR monitoring table.

 

[LoneWolf~]

ThrottleStop voltage control does not work when Windows VBS is enabled. Follow the link in my signature. Core isolation memory integrity needs to be disabled and anything else that depends on virtualization also needs to be disabled.

After you do that, reboot and delete the ThrottleStop.INI configuration file before running ThrottleStop. Post an updated FIVR screenshot. You should not be seeing a column of 0.3799 values in the ThrottleStop FIVR monitoring table.

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I didn't know what VBS was until I looked at the link you mentioned. All this time it was a small toggle! I've already got both CPU and CPU Cache at -110mV, thank you! Are there any other settings in Throttlestop you'd recommend changing?

 

[unclewebb]

Your undervolt is definitely working now. No more 0.3799 values showing up in the monitoring table is a good sign. That is like a big red flag whenever I see that.

Do some Cinebench testing. Some users with your CPU get better results when they increase only the core offset. There is no law that says the core and cache offsets must be set equal to each other. If -110 mV for the cache is stable, the core offset at approximately -175 mV might improve Cinebench temperatures or scores.

I like to set IccMax to the max, 255.75, for both the cache and the core.

Post a screenshot of the TPL window. You have good cooling so increasing the MSR power limits, PL1 to 60 or 70 and PL2 to about 90, might help the cause. Also check the MMIO Lock box when playing around with these settings.

 

[LoneWolf~]

I did a little basic testing using the built-in benchmark and it got the best result at -110mV for both CPU and Cache at 12.632s. At -150 CPU and -110 Cache it was a little slower at 13.092s.

Running Cinebench r23 with CPU -150 and cache -110 got the same results as both at -110 but cooler. 6711 and whlie the fans were going full tilt it didn't pass 84C while running Cinebench. Before I turned VBS off I was getting around 4500 in Cinebench so this is already a huge improvement in general. Thank you for walking me through all this I really appreciate it.

 

[unclewebb]

It is always a good idea to check the MMIO Lock box.

huge improvement

Lots of people live in fear that the world will come to an end if they disable VBS. I think they have been drinking too much Microsoft Kool-Aid.
Your results speak for themselves. Having VBS enabled can screw up a lot of older computers.

When using different offset voltages, you will either get better performance or you will get lower heat output and lower temperatures or less fan noise. An offset of -175 for the core might help a little more. At a certain point, going any further will make zero difference. Some like to use -200 mV or -225 mV but at this point, you are in the area of diminishing returns. Your temps are great so no need to undervolt any further. Too many people chase after the perfect voltage. Leaving a little bit of voltage head room is best to guarantee stability.

Thank you for walking me through all this I really appreciate it.

After all these years I still enjoy hearing about a ThrottleStop success story.