NitroSense Limits CPU to 60W Even in Turbo Mode (Ryzen 7 7840HS) on Nitro AN16-41

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Serwintes
Serwintes Member Posts: 13

Tinkerer

edited July 24 in Nitro Gaming

Hi everyone,

I’ve noticed that NitroSense is limiting my Ryzen 7 7840HS CPU to 60W even when Turbo Mode is enabled. The temperatures are totally fine — around 75–76°C — but the CPU stays stuck at 60W and around 4.3 GHz.

When I enable PBO (Precision Boost Overdrive) in the BIOS, the CPU can draw up to 80–90W, and clock speeds jump to 4.7–4.9 GHz, with temps rising to around 85–87°C. Everything seems stable, and thermals are still within safe limits.

The problem is that this high power state only lasts for a few minutes. After that, it drops back down to 60W again, and the CPU clocks settle back to 4.3 GHz — even though temps are still under control. It seems like NitroSense (or the firmware) is enforcing some sort of power limit regardless of the thermal headroom.

For those wondering, I enabled PBO through the advanced BIOS settings, which I accessed using the Fn + Tab key combination to unlock the hidden BIOS options.

Interestingly, I’ve seen MSI laptops with the same Ryzen 7 7840HS processor reaching and sustaining 80–90W using MSI Center software. Their systems also run at similar temperatures (85–87°C) and maintain high performance without being throttled.

Has anyone else experienced this? Is there a way to disable or bypass NitroSense’s power restriction so the system can sustain higher performance when temps allow?

Any help or suggestions would be appreciated!

Thanks!

[Edited the thread to add model name to the title]

Answers

  • Puraw
    Puraw ACE, Member Posts: 18,070 Trailblazer

    Hi Serwintes

    Based on your specs and BIOS access method, it sounds like you’re using a Nitro AN16-41 or AN17-41. Both models feature the Ryzen 7 7840HS and support PBO via the Fn+Tab unlock. If you can confirm the exact model ID (check under the laptop or in Acer Care Center), we can dig deeper into firmware limits and possible workarounds

  • Serwintes
    Serwintes Member Posts: 13

    Tinkerer

    I have a Nitro AN16-41 (R1PR) with an RTX 4070 and Ryzen 7 7840HS.
    I've already enabled PBO through the hidden BIOS settings.
    To access those, I start the laptop while holding down Fn + Tab, and when the Acer logo appears, I begin pressing F2.

    My issue is not with enabling PBO — it's already active. The problem is that even with PBO enabled and NitroSense set to Nitro Mode, my CPU wattage gets capped, seemingly by NitroSense or some internal power management.

    During the first 1–2 minutes of a Cinebench run, the CPU pulls 90–100W, as expected. But after that, I can never reach those watt levels again, even when I rerun the benchmark.
    There’s no thermal throttling — temperatures stay under control.

    It looks like NitroSense limits the wattage after a short burst, and it doesn’t allow the CPU to return to full power afterward, even though the system is clearly capable.

  • Puraw
    Puraw ACE, Member Posts: 18,070 Trailblazer

    Hi Serwintes,

    If you're hitting persistent wattage limits under NitroSense—even with PBO active—try this tweak:

    1. Go to Control Panel > Power Options > Edit Plan Settings > Advanced Settings.
    2. Under Processor Power Management > Processor performance boost mode, change both Plugged in and On battery to:
      • Aggressive At Guaranteed

    This setting prioritizes sustained boost as long as the system meets guaranteed conditions (thermals, firmware margins), which may help circumvent NitroSense’s fallback behavior.

    If you don't have this option you have to unhide it with Regedit.exe, change this value from 1 (hidden) to 2 (unhide)

    Turbo boost reg.jpg
  • Serwintes
    Serwintes Member Posts: 13

    Tinkerer

    I did what you said and it's still the same, stuck at 60 watts 4.3GHz. Its start at 90 watts 4.9GHz and always drop to 60 watts 4.3GHz

  • Puraw
    Puraw ACE, Member Posts: 18,070 Trailblazer

    Thanks for all the insights, Serwintes. Since you’ve already enabled PBO and tried the “Aggressive at Guaranteed” tweak with no lasting impact, it’s pretty clear NitroSense is enforcing a hard fallback—even when temps are well within safe range.

    I’d avoid any BIOS modding here. The best move might be to monitor official Acer BIOS updates for the AN16-41. If we’re lucky, future firmware might unlock more persistent PL1/PL2 behavior or give us finer-grain control over boost enforcement.

    For now, it seems this model has a built-in power ceiling that kicks in after brief bursts, likely tied to EC behavior. If you haven't done a full EC reset (battery pull or pinhole method), that could be worth trying—some folks report temporary uplift before fallback returns.

    Let’s keep eyes peeled for any upcoming BIOS changes. If I spot anything promising, I’ll loop back in. Appreciate you sharing the test results—it helps everyone map out what works and what doesn’t.