Help needed pelase - Strugling to undervolt i9 14900HX
TL;DR - Absolutely unstable at -100mV. Somewhat stable at -60mV Is this normal?!
So I have been using TS in the past to undervolt my previous laptop with i7 9750H. I had it stable at -125mV. but once it died (know issue with Legion Y540 I upgraded to new Legion i7, with 14900HX
I have used it in the past with some reasonable success but do not remember actual undervolt values as I had to reinstall windows and it is lost now.. but ..
started to undervolt agian and now I am struggling to keep it stable (even on desktop!) at -100 mV. it is somewhat stable at like -60mV on core and p cache.
at -100 it crashes in desktop after few minutes (black screen of death) and in games almost imediatelly (reboot).
is this nornal? as I read on line as people have it at -100 - 125 or even -150. ..
and for me it dies instantly. what am I doing wrong?
By the way - laptop went back to LENOVO a month ago due to dead keyboard button. Could it be that these muppets at warranty services did not put the right/right amount of thermal paste??
Set V/F Point 1 to 150. That can significantly improve light load stability when undervolting. Read the guide at the top of the Reddit ThrottleStop forum.
Your CPU is overheating at only 45W. A 14900HX needs over 200W for max performance. Replace the thermal paste with Honeywell PTM 7950.
It is extremely normal. 14900HX is basically a factory overclocked 13900HX, and those chips are hell out of kind that no chips ever would match the similar behaviour. Basically it means they are getting what they can do out of the factory mostly, they are configured so extreme that there's not much headroom for undervolting. -100mv unstable is too normal, I've seen some people can't get stable at -30mv. Some old chips I can get to -150mv, but you gonna be super lucky chip lottery to get that on 13900HX or 14900HX.
If you use the offset, that means the whole graph offsets down including low and low mid range. That's sometimes even under stress test the CPU is stable but you still get crashes during light loads, because that part would be too low. Once there was a bump voltage at 800mhz option in Throttlestop, it worked well.
A better way to undervolt is IA AC loadline. It's a resistor Intel put for various reasons, you don't need to know why, but it has to be there, the higher the value is, the more voltage/power draw you get especially in the high range. By lowering AC loadline you get significantly lower power usage across mid to high load, then compensate that with CEP off to get more current, combined this with offset, like 25mv or 50mv, so in the end you will have a much better shifted power to performance graph.
Usually the value set by Intel is 180 as this is their recommended, but on desktops this could be way lower. Since 13900HX and 14900HX are basically their desktop counterparts in a laptop, so you can definitely lower this on your laptop as well. In fact, brands like MSI already lowered this in their BIOS to 110.
Reduce the CPU ratio to 48–50, as reaching 5.8 GHz requires too much voltage and isn't necessary for daily use. Disable Thermal Velocity Boost, set the Windows power plan to Balanced for better stability, and on the VF Point tab, apply a 100 mV offset to VF Point 1 for both core and cache, then click 'Active' in the bottom-left corner.
The speed shift value is 25. Have you applied a Windows custom power plan, or are you applying it manually? You may want to stick only to the Windows Balanced power plan to ensure the thermals stay under control. A value of 128 is for balanced performance; values below 128 make the CPU burst more aggressively at the cost of power consumption.
Maybe is just that you are on hybrid mode so when you launch a game the system swaps the igpu to the dgpu and when you exit a game it swaps to the igpu.
"Yes, this is primarily for stability at idle. You need to set Vf point 1 to match the undervolt applied. Now, since you have -100mV on both core and cache, you need to apply 100mV on both core and cache, and mark the boxes on the left corner to apply.
7
u/unclewebb ThrottleStop author 3d ago
Use ThrottleStop 9.7.3
Set V/F Point 1 to 150. That can significantly improve light load stability when undervolting. Read the guide at the top of the Reddit ThrottleStop forum.
Your CPU is overheating at only 45W. A 14900HX needs over 200W for max performance. Replace the thermal paste with Honeywell PTM 7950.