ASUS Crosshair V Formula-Z
| ASUS Crosshair V Formula-Z | |
|---|---|
 | |
| Overview | |
| Introduced | 2012 |
| Manufacturer | ASUS |
| Specifications | |
| Socket | 1x AM3+ |
| Northbridge | AMD 990FX |
| Southbridge | AMD SB950 |
| Super I/O | ITE IT8721F |
| Memory | 4 slots (2 channels) DDR3-1600 ECC UDIMM, up to 64GB |
| BIOS Flash | 8 MiB socketed DIP-8 (W25Q64FVAIG) |
| Form Factor | ATX |
| Power Inputs | 1x 8-pin EPS |
| Expansion Slots |
|
| Onboard Peripherals | |
| Serial Interface | One internal |
| Audio Interface | Integrated (SB950 HD Audio), ALC892 codec |
The ASUS Crosshair V Formula-Z motherboard was recently ported to coreboot-15h.
Open Source Firmware
Open source firmware for the Crosshair V Formula-Z is provided by coreboot-15h utilizing AMD's open source AGESA and CIMx releases for platform initialization. The git repository for the firmware can be reviewed here.
coreboot-15h
Release
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Notes
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Download Options
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| 2026.05.27-v4.11-57e26bdcd95 |
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Fan Output
The Crosshair V Formula-Z has three main fan zones: CPU, CHA, and OPT. The various fan headers on the motherboard are labeled accordingly. The CPU and CHA fan zones are controlled by the ITE IT8721F. The OPT fans are controlled by the EC. In coreboot-15h, CPU fans are setup for PWM control and will respond to changes in CPU temperature. The CHA fans are setup for voltage control and will respond to both the CPU temperature and the 990FX temperature. The OPT fans will operate at full speed.
Missing Features
- Hibernation and Suspend/Resume are unsupported.
- CPUs using the K10 microarchitecture are unsupported.
Flashing
To switch from the stock firmware to coreboot, external flashing is required. It is recommended to update the OEM BIOS to the latest version (2201) before switching to coreboot-15h, this will update the EC firmware to the latest version (GMED-0005). The DIP-8 flash chip is located between PCIE_X8_2 and PCIE_X16/X8_3 (labeled BIOS in the motherboard diagram). A 3.3V CH341a programmer can be used to flash coreboot onto the Crosshair V Formula-Z. When switching to coreboot-15h from the OEM BIOS, clearing the CMOS is required. The original DIP-8 flash chip requires the following flashrom argument:
flashrom -c "W25Q64BV/W25Q64CV/W25Q64FV"
Clearing the CMOS
- Turn off the computer, disconnect the power cord and any powered peripherals (Monitors, USB devices, etc)
- Remove the CMOS battery
- Wait 20 seconds
- Reinstall the CMOS battery
- Connect the power cord
- Wait 2 minutes
- Turn on the motherboard
CMOS Battery
The motherboard requires a 3V CR2032 battery for reliable operation. Without a working CMOS battery, a two minute wait is always needed between connecting the motherboard to power and turning it on. This requirement is shared both by the OEM BIOS and coreboot-15h.
Deployed Systems
Motherboard Diagrams
Motherboard Components
Socket AM3+
AMD Socket AM3+, also known as Socket AM3b or Socket AM3r2, is compatible with a subset of AMD Orochi processors. It is backwards compatible with K10 processors designed for the AM3 socket, but these are not yet supported by coreboot-15h.
Official Documentation
Processors
Orochi FX (Zembezi and Vishera) and Opteron (Zurich and Delhi) processors are compatible with the AM3+ socket. TDP ratings for these processors range between 25 W and 220 W. Each AM3+ motherboard has a maximum supported TDP for CPUs. For example, the Supermicro H8SML is only designed to support up to 65 W processors.
Official Source Code and Documentation
- AGESA Source Code
- AGESA Interface Specification
- BIOS and Kernel Developer's Guide
- Product Data Sheet (FX)
- Product Data Sheet (Opteron)
- Software Optimization Guide
DDR3 Memory
PCIe 2.0 Slots
| Slot | Width | Wired Lanes | Notes |
|---|---|---|---|
| PCIE_X16_1 | x16 | x16 | |
| PCIEX1_1 | x1 | x1 | Wired to the SB950 |
| PCIE_X8_2 | x16 | x8 | Disables if no card is detected. |
| PCIEX1_2 | x1 | x1 | Wired to the SB950 |
| PCIE_X16/X8_3 | x16 | x8 or x16 | Switches to x16 mode if PCIE_X8_2 is empty. |
| PCIE_X4_4 | x16 | x4 |
AMD 990FX
The AMD 990FX is a high-performance enthusiast chipset launched in 2011 for Socket AM3+ processors, offering robust support for AMD FX-Series (Bulldozer/Vishera) 8-core CPUs and multi-GPU setups. Key features include 32 PCIe 2.0 lanes, native SATA 6Gb/s, USB 3.0, and strong overclocking capabilities, often paired with the SB950 southbridge.
Official Source Code and Documentation
- CIMx Source Code
- Databook
- BIOS Developer's Guide
- Register Reference Guide
- Register Programming Requirements
- Errata
- IOMMU Specification
Part Numbers
- AMD 215-0716046
AMD SB950
The AMD SB950 is a Southbridge chipset designed for Socket AM3+ and AM3 motherboards, specifically supporting AMD FX, Phenom II, Athlon II, and Sempron processors. Released to accompany the 900-series Northbridge (990FX/990X/970), it brings native SATA 6Gb/s support for fast storage and 6x SATA ports, generally offering high compatibility for DDR3-based systems.
Official Source Code and Documentation
Related Source Code and Documentation
- SB800 CIMx Source Code
- SB800 BIOS Developer's Guide
- SB800 Register Reference Guide
- SB800 Register Programming Requirements
- SB800 Product Databook
- SB800 Product Errata
Part Numbers
- AMD 218-0697031
ITE IT8721F
The ITE IT8721F is a highly integrated Super I/O using the Low Pin Count Interface. It provides the most commonly used legacy Super I/O functionality plus the latest Environment Control initiatives, including H/W Monitor and Fan Speed Controller.