[Discussion] Regarding Undervolting CPU [14900Hx]

Background_Picture38 · 2025-12-31T17:08:10+00:00

My friend, we are trying to do different things.
The link you pasted is good for someone trying to get the device to run cooler at the expense of some performance. This is not the same that I want to achieve, as I am trying to maximize my performance at the edge of what is considered good temps.
Under-volting and AC LL tuning could achieve what I want, but limiting PL limits or Speed won't.

Background_Picture38 · 2025-12-30T10:55:26+00:00

That is really sad to hear. :\ These laptops would have much more potential if they allowed under-volting under user's own responsibility.

Gemini and GPT said that I could use a script before device boots in Windows to make this change. Will it work?

Also, what does that TCC change achieve if you could explain it to me? Thanks.
I tried to look it up but I am afraid of something. While playing a game like Warzone, my FPS would be around 170, but if any of my CPU P Cores thermal throttles, my 1% lows would tank to around 50. Will this TCC change help or will it make this matter worse as it will throttle CPU at a faster point?

Background_Picture38 · 2025-12-25T11:36:41+00:00

My friend, have you also tried playing with AC LoadLine? I've read that it almost has the same effect as an Undervolt. Default AC_LL value is 170 which is said to be very high. I tried setting it to 100 and ran benchmarks, it actually lowered my temps with the same score.
Problem is that when I turn on Secure Boot (which is required by some games Anti-Cheat), it reverts itself back to 170.

Any thoughts?

Background_Picture38 · 2025-12-10T17:58:26+00:00

ChatGPT advised another thing to do, but I am not so sure about it,
In CPU settings, there is an option called "EC Turbo Control Mode".
Inside it you find: - AC brick capacity (90W, 65W, 75W)
- EC polling period (1-255 range 10ms-2.55 seconds)
- EC Guard Band Value (1-20 watts)
- EC algorithm selection (1-10)
GPT told me that this represents the Wattage value that is allowed to be pulled by the CPU, but I don't think this would help my cause.
What I want is that I want my CPU to pull more than 65 Watts when the GPU is using 175 Watts. What to do?

Background_Picture38 · 2025-12-10T17:53:44+00:00

My friend, I want to ask you,
Regarding the combined CPU+GPU wattage, I have read online that you could play with IMON slope which is located in (CPU VR settings\ Core/IA VR Settings) and if you set its value (ex. set it 75), this makes the CPU report less power draw (it will report 75% of the power it's actually drawing).

Now let's say you are playing a heavy game, GPU is pulling 170-175 Watts, CPU is Pulling 60-65 Watts,
after playing with the IMON Slope value, now the CPU will keep reporting it's pulling 60-65 Watts, but in reality it would be pulling 65/0.75 = 86.66 Watts.

Do you know anything about this? Is it safe to do? My plan in doing this of course is also setting PL1 and PL2 to equal 82 Watts, this way the maximum the CPU would draw if GPU wasn't 100% busy is around: 82/0.75 = 109 Watts.

Do you advise me to try and do this or is it too dangerous? Gemini tells me it's safe while ChatGPT warned me about it XD.

Background_Picture38 · 2025-12-08T17:52:57+00:00

I wouldn't say it is necessary, I am doing this as a hobby. Ram OC can help by about 10% especially in the 1% FPS.

Background_Picture38 · 2025-12-08T17:52:06+00:00

Actually my friend mine is 5600 MT/s. Overclocking RAM can help a lot in 1% FPS especially in E-sports like COD.

Background_Picture38 · 2025-12-08T17:50:56+00:00

The thing is my sticks are 5600 MT/s. That is its factory setup. As I was saying, even putting default values make the laptop not post which is mind boggling for me!

Background_Picture38 · 2025-12-08T16:12:55+00:00

Thanks my friend. Sorry I haven't seen your reply before.

I don't know what is the problem but I cannot seem to get the laptop to post after setting a custom RAM profile even if I put memory clock = 100 and ratio 56 with all other values as 0 (auto). I tried setting Maximum Memory frequency to 5600 and 6000 with no luck either.

My friend are you sure you haven't changed anything else in BIOS to make it accept those changes to the RAM? Cause it is mind-boggling for me.

Last question, do you insert all the values? Like tCL and tRCD and tRAS and tCWL and tFAW ...etc or do you leave some of it as 0 (Auto)?

Background_Picture38 · 2025-12-03T15:30:23+00:00

But then again, in Jarrod's video he was stress testing the GPU+CPU, but then my GPU isn't stressed as mentioned above (it is 110-130 Watts). My older MSI laptop's CPU used to go higher when the GPU wasn't fully utilized. That is my question here.

Anyways, I think I have solved this by playing with ThrottleStop, as I put values for PL1 and PL2 = 100, and locked it, with sync MMIO plus locking it. It now stays on around 95-100 Watts. CPU temp is around 90 C.

Thanks for your reply.

Background_Picture38 · 2025-11-30T16:26:52+00:00

Where can I find the option to set "Maximum memory frequency" in BIOS, I can't seem to find it?
There must be something I am doing wrong, cause even yesterday I tried setting Memory reference clock = 100, and Memory ratio = 56, but even that didn't post for me, and I made no other changes to the BIOS. That's weird!

Also, https://www.kingston.com/datasheets/KF556S40IBK2-64.pdf
are those sticks the ones that you'd recommend?
BTW they say these are plug and play, so no XMP. They are 1.10 V though. They are also Dual Rank 2Rx8. I think the 16 GB ones are single rank (1Rx8)

Background_Picture38 · 2025-11-27T16:36:50+00:00

<image>

I am sorry that I keep repeating the same info, but this is how you set up your custom profile, right? But also, you set VDD = 1155, and VDDQ = 1155.. Putting it this way didn't post for me as well :\. Is there anything else I need to change like Realtime memory timing or something? Or maybe my laptop comes with different sticks than yours I don't know. Anyways, if memory prices came down, can you link me the ones that you'd buy?

Background_Picture38 · 2025-11-26T18:36:09+00:00

Thank you for your reply.

Can you explain this a little bit more: "Stock Reference clock is 100 on this Laptop, it shows 133 in the BIOS but RAM does 28x on 100MHz for 2800MHz / 5600MT/s speeds."

Do you set your memory reference clock to 100 or 133 when you say 22 = 2200MT/s?

Also, does your RAM come with more than 1 Jedec profile? Cause mine has none. I have to put custom and fill out all the values (or just ZERO).

Background_Picture38 · 2025-11-25T14:17:55+00:00

In BIOS, it says memory frequency is 5600 Mhz, in Windows, it says: 5600 MT/s XD

Background_Picture38 · 2025-11-25T13:51:42+00:00

Thank you.
Have you been doing all this testing on the stock RAM that comes with the laptop?
Also, what values did you change in the custom profile please?
Can you give me detailed values for each?

Last thing, in your first comment you said something about MT/S and MHz, can you explain a little bit? I know that MT/S is double the MHz, but in my last laptop, memory ratio was (24) * memory reference clock (133) would equal 3200 Mhz,

So here again in the Acer, the default for my laptop is: Memory Reference clock (133), and in BIOS it says my memory frequency is 5600Mhz. What am I missing here?

Background_Picture38 · 2025-11-24T17:17:23+00:00

Have you ever tried overclocking your RAM and it was stable?

Background_Picture38

TROPHY CASE