ROG Ally X: Best AC.xml for 25W High-Performance Mode

The objective is to flatten the SPL, SPPT, and FPPT values to a unified 25W to ensure the “Sustained Power Limit” ($P_{sustained}$) is constant, eliminating frame-time stuttering.

File Path & Engineering Setup

1. Navigate to:C:\ProgramData\ASUS\ArmouryCrate\UserCustomProfiles\
   • Note: If you haven’t created a manual profile in the GUI yet, this folder may be empty. Create one in Armoury Crate first to generate the template.
2. Tool Recommendation: Use Notepad++ to edit the .xml values.
3. Pro Tip: In 2026, many users prefer G-Helper as a lightweight alternative to Armoury Crate. If you use G-Helper, these same logic principles apply to its config.json, but the XML method below is for the native ASUS ecosystem.

Optimized “Stable-Peak” 25W XML Parameters

XML Tag	Value	Technical Purpose
<SPL>	25	Sustained Power Limit. The target wattage for long sessions.
<SPPT>	25	Slow Package Power Tracking. Prevents the 2-minute heat spike.
<FPPT>	25	Fast Package Power Tracking. Prevents the 10-second thermal burst.
<Fan1_Curve>	75% @ 75°C	Custom aggressive curve to keep the APU under 80°C.
<CPU_Boost>	False	The Master Fix. Disables clock-speed “chasing” for smoother 1% lows.

<Profile Name="GameEngineer_25W">
  <PowerLimits>
    <SPL>25</SPL>
    <SPPT>25</SPPT>
    <FPPT>25</FPPT>
  </PowerLimits>
  <FanCurves>
    <Fan1>30,40,50,60,70,80,90,100;15,25,35,50,65,75,85,100</Fan1>
    <Fan2>30,40,50,60,70,80,90,100;15,25,35,50,65,75,85,100</Fan2>
  </FanCurves>
  <EcoAssist>
    <CPUBoost>Disabled</CPUBoost>
  </EcoAssist>
</Profile>

HowTo: Engineering the 25W Manual Pipeline

Follow these GameEngineer.net technical steps to optimize your ROG Ally X:

1. Flattening the Wattage Curve: Default Turbo mode boosts to 53W ($P_{max}$) and then drops to 30W. This fluctuation causes the GPU clocks to “dance,” resulting in uneven frame delivery. By setting all three limits (SPL, SPPT, FPPT) to 25, you create a rock-solid power floor.
2. Disabling CPU Boost: In 90% of modern games, the CPU is not the bottleneck; the iGPU is. Disabling CPU Boost in the XML prevents the processor from hitting 4.5GHz+ and generating excess heat, leaving more thermal headroom for the GPU to stay at its maximum clock ($G_{clock}$).
3. The Fan Curve Protocol: The ROG Ally X has a vastly improved cooling system over the original. We recommend a “75 at 75” rule: when the APU hits 75°C, fans should be at 75% speed. This keeps the device cool enough to touch while preventing thermal throttling.
4. VRAM Allocation Synergy: For 25W play, ensure your VRAM is set to 8GB in Armoury Crate. At 4K or 1440p (via RSR), 25W is enough power to actually utilize that extra memory buffer.
5. Validation: After saving the XML, restart the ASUS Optimization Service in services.msc or simply reboot. Your new “GameEngineer_25W” profile will appear in the Command Center.

Technical Explanation: Diminishing Returns ($R_{dim}$)

In handheld engineering, the relationship between Wattage and FPS is not linear.

$$FPS \approx \sqrt{Wattage} \times Efficiency\_Constant$$

On the Z1 Extreme, the jump from 15W to 25W provides a massive performance gain ($\sim 35\%$). However, jumping from 25W to 35W only provides a marginal gain ($\sim 5-8\%$) while increasing heat output by over 40%. By locking your AC.xml to 25W, you are operating at the peak efficiency of the RDNA 3 architecture, ensuring the longest possible life for your handheld’s internal components.