This repository contains a highly optimized, EC-verified Notebook FanControl (NBFC) configuration file for the HP EliteBook 840 G3 and related HP EliteBook models.
If your HP laptop suffers from a loud, whining fan at idle, or if it constantly thermal throttles under heavy load, this custom XML profile safely takes control of the Embedded Controller (EC) to provide a quiet, balanced thermal curve.
This configuration was built specifically for the 840 G3, but shares Embedded Controller (EC) logic with the following HP laptops:
- HP EliteBook 840 G3
- HP EliteBook 850 G3 (Untested, but likely compatible)
- HP EliteBook 820 G3 (Untested, but likely compatible)
- HP EliteBook 745 G3 (Untested, but likely compatible)
- HP ZBook 14u G3 (Untested, but likely compatible)
- Loud Fan at Idle: Keeps the fan completely off at 0% when the CPU is under 44°C.
- Aggressive BIOS Override: Tricks the HP BIOS by constantly writing a "fake temperature" to the EC (Register 38), preventing the BIOS from stealing fan control back from NBFC.
- Thermal Throttling: Ramps the fan up to 100% at 85°C to prevent the CPU from hitting the 100°C critical throttle limit.
- Download and install Notebook FanControl (NBFC).
- Download the
HP_EliteBook_840_G3_Optimized.xmlfile from this repository. - Move the XML file into your NBFC configs directory (Usually located at
C:\Program Files (x86)\NoteBook FanControl\Configs). - Open the NBFC application.
- Click the gear icon to open Settings.
- Select HP EliteBook 840 G3 Perfect from the dropdown menu and apply.
- Ensure the service is "Enabled".
For those looking to tweak this further, here are the verified EC registers used in this build:
- Fan Read Register:
0x2E(46) - Fan Write Register:
0x2F(47) - HP Thermal Zone Select:
0x22(34) - Fake Temperature Write:
0x26(38)
Keywords for Search: HP 840 G3 fan noise fix, HP EliteBook loud fan, Notebook FanControl HP 840 G3, NBFC config HP Elitebook, HP 850 G3 fan control, HP EliteBook overheating fix.