What’s Inside an X99 DMG 2 Hackintosh Installer and How to Inspect It Safely

When you search for a ready-made macOS installer for an X99 Hackintosh, you'll find files labeled “X99 DMG 2” or similar variants. These disk images are not official Apple distributions. They are pre-packaged, third-party builds that bundle a macOS installer with a bootloader (usually Clover or OpenCore), kexts, ACPI tables, and configuration files tailored to the X99 chipset. The “2” in the name typically indicates a revision or a second version of a specific packager’s image — it does not correspond to any Apple version number. This article explains what these images contain, why they are risky, and how to inspect them safely before writing them to a USB drive.

Let's start with what's actually inside one of these images. A typical X99 DMG 2 is a compressed read-only disk image (UDIF or zlib-compressed) that, when expanded, shows a single partition with the following structure:

• macOS installer app — usually a copy of macOS Sierra (10.12), High Sierra (10.13), or Mojave (10.14), extracted from a genuine Apple installer and then repackaged. The version is often indicated in the filename, but not always reliably.
• EFI partition contents — a complete EFI folder with a bootloader (Clover r4000–r5100 series or OpenCore 0.5.x–0.6.x), configuration plist, ACPI patched tables (.aml files), and a kexts folder (Lilu, WhateverGreen, AppleALC, FakeSMC/VirtualSMC, USBInjectAll, X99-specific SSDTs).
• Optional extras — scripts for post-installation, a README text file, sometimes a pre-configured config.plist for specific motherboard models (ASUS X99-A, Gigabyte X99-UD4, MSI X99A SLI Plus).

The packager has already applied common fixes: X99 ACPI patches (PMCR, XHCI, HPET), USB port limit removal, and iGPU disable (since X99 CPUs have no iGPU). The image is designed to boot on a wide range of X99 hardware, but “wide range” doesn’t mean it will work on your exact configuration.

Why “X99 DMG 2” Is Not a Standard Apple Image

Apple never distributed macOS in a DMG that contains an EFI folder with third-party bootloaders. The official macOS installer DMG (from the App Store) contains only the Install macOS.app bundle and a small BaseSystem.dmg. An X99 DMG 2 is a modified distribution. The modifications include:

• Replacing the boot.efi with a patched version or injecting a bootloader into the UEFI boot chain.
• Adding kexts that are not part of macOS (FakeSMC, VirtualSMC, Lilu, etc.).
• Applying ACPI table overrides that may work on one motherboard revision but cause panics on another.

Because these images are created by community members with varying levels of testing, there is no guarantee that the included ACPI patches match your BIOS version or firmware quirks. Using an untested DMG directly can lead to kernel panics during boot, broken sleep/wake, or Ethernet/audio not working.

How to Inspect an X99 DMG 2 Safely

Before copying the image to a USB drive, always inspect its contents on a separate machine or in a sandboxed environment. Here is a step-by-step procedure:

1. Verify the checksum — the packager should provide an MD5 or SHA-256 hash. Compare it after download. If no hash is published, treat the file as untrusted.
2. Mount the DMG without booting — on a working macOS system (even a real Mac or a separate Hackintosh), double-click the DMG to mount it. Do not run any installer scripts yet.
3. Browse the EFI folder — open the EFI partition or the root of the mounted image. Look for the EFI/CLOVER or EFI/OC folder. Examine the config.plist with a plist editor (Xcode, PlistEdit Pro, or even a text editor). Check for:
• SMBIOS settings: are they set to a MacPro6,1 or iMacPro1,1? These are appropriate for X99.
• ACPI patches: look for SSDTs named SSDT-X99.aml or SSDT-UIAC.aml. Compare the table signatures with known working patches for your board.
• Kexts: ensure FakeSMC.kext or VirtualSMC.kext is present. If both are present, one may conflict.
4. Check the installer version — inside the mounted image, locate the Install macOS.app. Right-click and select “Show Package Contents,” then navigate to Contents/SharedSupport/InstallESD.dmg. Mount that and check the SystemVersion.plist to confirm the exact build number (e.g., 17G66 for High Sierra 10.13.6). If the build is mismatched with the stated version, discard the image.
5. Scan for malware — use a tool like KnockKnock or BlockBlock (on a real Mac) to check for launch agents or kernel extensions that may phone home. Any unsigned kext that is not a known Hackintosh project (Lilu, WhateverGreen, etc.) is suspicious.

If any of these steps reveal anomalies — mismatched build number, unknown kexts, or ACPI tables that reference a different motherboard — do not use the image. Instead, build your own installer from a genuine macOS copy and apply only the patches you have verified for your specific board. Our earlier guide on Clover vs OpenCore for Legacy Hackintosh: X79, X99, Z170, Z270 on Sierra Through Mojave covers the differences in bootloader configuration that are relevant here.

Common Pitfalls with Pre-Built X99 Images

ACPI Table Conflicts

X99 motherboards from ASUS, Gigabyte, ASRock, and MSI all use slightly different ACPI implementations. A DMG 2 image might include a SSDT that renames _OSI to XOSI or adds a _DSM method for USB power. On a different board, that same SSDT can cause a “ACPI Error: Method parse/execution failed” panic at boot. If you encounter such an error, you can disable the offending SSDT by removing it from the EFI/CLOVER/ACPI/patched folder (or the equivalent in OpenCore) and rebooting. However, this is a trial-and-error process that risks data loss if the system is not backed up.

USB Port Limit and Sleep Issues

Many X99 DMG 2 images include a pre-made USBInjectAll.kext with a SSDT-UIAC.aml that maps ports for a specific board. If your board has a different USB controller (e.g., ASMedia vs Intel), the port map will be wrong, leading to USB 3.0 devices not enumerating or sleep/wake failure. The Fixing ACPI Sleep and USB Wake Issues on Legacy Hackintosh Builds article explains how to create a custom USB map for your exact hardware — a step that is almost always necessary when switching from a generic DMG image to a reliable daily driver.

Ethernet Kext Version Mismatch

X99 boards commonly use Intel I218-V or I210-AT Ethernet controllers. The DMG 2 may include IntelMausiEthernet.kext or AppleIntelE1000.kext. However, older versions of these kexts (pre-2018) do not support the I218-V on High Sierra 10.13.6 without a board-id spoof. If Ethernet does not work after installation, check the kext version and replace it with the latest release from the developer’s repository. Do not use kexts from unknown sources.

Practical Inspection Example: Reading the Config.plist

Suppose you have mounted an X99 DMG 2 and opened EFI/CLOVER/config.plist. Navigate to the ACPI section. You see a list of patches like:

<dict>
  <key>Comment</key>
  <string>change _OSI to XOSI</string>
  <key>Find</key>
  <data>X09PSQ==</data>
  <key>Replace</key>
  <data>WE9TSQ==</data>
</dict>

This rename is common for X99 boards to enable macOS-native power management. It is generally safe. But if you also see a patch that renames “EHC1” to “EH01” on a board that does not have an EHC1 controller, that patch is useless and may cause a harmless log line — but it will not break boot. More dangerous are patches that inject a device property like device-id for the SATA controller. If the injected ID does not match your chipset (e.g., using a C610 ID on a C612 chipset), SATA drives may not appear in Disk Utility. In that case, you must remove or modify the property injection in config.plist before booting.

After inspecting the plist, check the kexts folder. A healthy X99 DMG 2 should contain at minimum:

• Lilu.kext (v1.3.0 or newer for High Sierra)
• WhateverGreen.kext (v1.2.0 or newer)
• VirtualSMC.kext (or FakeSMC.kext, not both)
• AppleALC.kext (for audio)
• IntelMausiEthernet.kext (or AppleIntelE1000.kext)
• USBInjectAll.kext (or a pre-built USBMap.kext)

If you find kexts named “NullCPUPowerManagement.kext” or “DisableTurboBoost.kext,” the image is outdated and intended for older OS X versions (Yosemite/El Capitan). Those kexts are not needed on X99 with High Sierra or Mojave, and they can actually prevent proper CPU power management.

Risks of Blindly Writing the DMG to a USB Drive

The most immediate risk is overwriting your existing EFI partition without a backup. If the DMG 2 image contains a broken bootloader configuration, you may lose the ability to boot your current macOS installation. Always back up your EFI folder to a FAT32 partition on a separate drive before writing any new image. The second risk is data corruption: if the ACPI patches in the image cause a kernel panic during the first boot, the installer may attempt to write to the system partition before the panic, leaving an inconsistent filesystem. For this reason, always perform the first boot from the DMG 2 with your target drive disconnected or with a test SSD that contains no important data.

Some X99 DMG 2 images circulating on forums include modified versions of Apple’s IO80211Family.kext or IOBluetoothFamily.kext that claim to enable Wi-Fi on unsupported Broadcom cards. These modifications are unsupported and can break system updates. Even if they work initially, a future macOS security update may replace the patched kext with the stock version, causing Wi-Fi to stop working. The only safe approach is to use a genuine Apple-supported Broadcom card (BCM94360CD or similar) and avoid kext-level hacks for networking.

If after inspection you decide to proceed with the DMG 2, use a tool like Terminal’s dd or BalenaEtcher to write the image to a USB drive. Do not use Finder’s “Restore” function on the DMG directly, because that will copy the entire disk image structure rather than creating a bootable volume. After writing, boot from the USB and watch for verbose messages. If you see “Waiting for root device” or a stuck “PCI configuration begin,” the image’s ACPI patches are incompatible with your board — power off and revert to a known-good EFI backup.

Building your own installer from a genuine macOS download and applying only board-specific patches is always the safer path. The generic X99 DMG 2 can serve as a reference or a starting point, but it should never be your only boot solution without thorough verification.