The log file shows lots of power limit throttling right at 30W. I assume that is the cross load power limit that is being enforced. With this 30W power limit and your reduced 85°C thermal throttling temperature, the CPU will spend most of its time alternating between thermal throttling and power limit throttling.
Indeed, I ultimately realized I was on the wrong path there. I have since decided to go with higher power limits and a BD PROCHOT setting of 97 (using LLT for those, no interference with TS)
Most Lenovo Legion laptops have decent cooling. If I owned your laptop I would be ordering some Honeywell PTM 7950 immediately.
Not so fast with repasting - Lenovo uses a custom variant of that, the PTM7958, on Legions:
Lenovo's Stock Paste is Actually PTM7958 - A custom version of PTM7950 : r/LenovoLegion (reddit.com)
...which I was able to confirm with my Premium Care technician a year ago when I had my thermal module and motherboard replaced due to fan issues.
Either your laptop is overdue for a thorough cleaning or the heatsink was not properly installed.
I watched the technician put things back together so the latter is definitely out of the question. Guess what - it was due a thorough cleaning, which I stupidly didn't do recently, even though I have a nice mini-blower/vacuum for this purpose, i.e. suitable for laptops. I still remember the light "mist" of dust that came out of my vents once I used that the other day! Not too much, but clearly enough to thermally muffle the laptop.
LESSON, PEOPLE - clean your laptop vents and, if necessary, beneath the bottom cover every 6-12 months and only then continue down the checklist for methods to reduce temps/throttling.
Many users that have tried to use ThrottleStop to undervolt their 12th Gen mobile CPUs have run into problems. The on chip cache used by Intel has problems running reliably at max speed. This problem was fixed starting with the 13th Gen HX CPUs.
I'm confident that there are ways around this in order to achieve an optimal thermal/performance mix. Some evidence further down.
Different manufacturers used different methods to slow the cache down. Before undervolting, I would start by lowering the Cache Ratio Max value in the FIVR window from 46 to 36. The FIVR monitoring table shows that your cache is presently running at a reduced multiplier of 36. Setting Cache Ratio Max in ThrottleStop to a lower value will help with stability. After you do some undervolting, you can decide if you want to try increasing the Cache Ratio Max value.
Indeed, the main advice from experienced Legion users is: reduce Cache Ratio max to 32-34, when undervolting. That should work for most people. As you have yourself mentioned before, minimally it should be equivalent to the base CPU speed, i.e. 28 in my case; I will keep it at 32 until I have reasons to reduce it further. I have it at 36 for non-undervolted profiles.
For voltage settings, I would adjust the core and the P cache by -50 mV. If that is stable you can try -75 mV and then -100 mV. I have never owned a 12900HX so off the top of my head, I have no idea what voltage values will work best. It is all trial and error.
Standard advice for Legion mV offsets is -120/-100/-100 for Core/P-Cache/E-Cache. However, as already mentioned elsewhere in this forum, E-Cache undervolting may not benefit or even be detrimental to the whole effort, so I am not doing that. The stable settings I have for the other two are -110/-100 at the moment. I might venture further down on the Core offset at some point.
To improve stability, I would set the mV Boost box in the FIVR window to whatever undervolt values you are using. Set mV Boost to 50 or 75 or 100 or beyond if necessary. This setting can really help with light load stability issues when undervolting HX processors.
Indeed, I have it at -150 to be safe. However, waking up the laptop would still trigger a BSOD; I ticked the FIVR Sleep Defaults for Cache Ratio and Voltage and the problem seems to have gone away - may be worth advising others too, especially if they have already reduced their Cache Ratio anyway.
Is disabling Sleep mode another potential fix? Using Hibernation as an alternative?
In normal circumstances you could look into reducing the CPU speed. In your situation, the CPU is already throttling so badly that it is running at only half of its rated speed. The cooling really needs to be significantly improved. That is the main problem.
Not anymore! I attach a gaming session log with pretty much the same workload as my previous log. "Game" profile used, with Legion Performance Mode active, i.e. PL1=125, PL2=175. I hope you will notice not just the vast improvement but maybe also further tips on the current settings below:
(TPL window captured using "Performance" profile on Legion Custom Mode, i.e. PL1=90W, PL2=135W, PL1-cross-load=60W)
FPS are at an acceptable level. I reset my Windows 11 from scratch before testing again. I am still to install some software that may affect negatively, but I will keep a close eye on those to determine if they are to blame or not. Also, I am yet to perform a full GPU optimization to get closer to my 100FPS target; I am confident it is reachable using the means at my disposal.
Do a Google search for 12900HX ThrottleStop. There are other users with the same CPU you have. They might have a better idea of what offset voltage values will work well.
This forum, certain YouTube videos, r/LenovoLegion and the Legion Series discord are my best references. Most of the results of the suggested Google search lead there anyway - a good way for others to follow their path to throttle-free working and gaming!
Thanks on behalf of all the people you have helped with your great application! We all hope you will find the time to enhance it further soon.
You have the best help up here already.
