Small by design
The README describes the EFI as reduced to roughly 3 MB by removing unnecessary patches and settings.
OPENCORE · HASWELL · H81
A minimal EFI for a very specific machine.
A compact OpenCore EFI built around 4th-generation Haswell i3/i5 systems with Intel H81, HD4400–HD4600 graphics and ALC662 audio. The repository emphasizes stability, small size and removing unnecessary patches.
machine / target
Haswell i3 / i5
Intel H81 chipset
HD4400 → HD4600
ALC662 audio
repository builds
OpenCore 0.6.9 · High Sierra → Big Sur
OpenCore 0.8.1 · Monterey
✓ minimal configuration
✓ fast boot focus
! modify PlatformInfo before use
Haswell i3 / i5
Intel H81 chipset
HD4400 → HD4600
ALC662 audio
repository builds
OpenCore 0.6.9 · High Sierra → Big Sur
OpenCore 0.8.1 · Monterey
✓ minimal configuration
✓ fast boot focus
! modify PlatformInfo before use
01 / PROJECT IDEA
Less EFI, fewer moving parts.
The repository's own rule of thumb is simple: OpenCore does not get better by accumulating more patches and drivers. Stability matters more than chasing every new release.
Hardware-specific
Built around Haswell i3/i5, H81, HD4400–HD4600 and ALC662 rather than pretending to be a universal EFI.
Stability first
The project explicitly argues that a working, stable OpenCore version is more useful than upgrading merely because a newer release exists.
02 / REFERENCE MACHINE
The configuration it was built around.
These values are the repository author's machine, not a promise that every H81 system is identical.
CPUIntel Core i5-4590, 3.3 GHz quad-core
GraphicsIntel HD4600 + NVIDIA Quadro K600
MotherboardIntel H81 chipset · Colorful C.H81M V22
Memory16 GB DDR3 1600 MHz
Wi‑Fi / BluetoothBCM94360CD / Fenvi T919
AudioALC662
03 / USE
Match the EFI to the system.
The repository carries separate EFI directories for different macOS generations. Installation notes also distinguish debug and production configuration files.
Before booting
Modify PlatformInfo for your own machine. Intel Wi‑Fi/Bluetooth and USB 3.0 may require additional patching depending on hardware.
Known limitation
The README states that everything was working on the author's office computer except iMessage.
The repository documents High Sierra through Monterey-era configurations. Its Ventura entry was still marked “under development” in the 2023 README, so treat it as a historical hardware-specific EFI project rather than current universal macOS guidance.
The engineering principle behind it
The project follows a practical rule that still holds up: remove what is unnecessary, optimize for the actual machine, and stop changing a stable system without a reason. Its small EFI size and hardware-specific scope are consequences of that choice, not goals in isolation.