macOS Big Sur 11.3 Beta 3 has broken Mac Pro's early-2009 to mid-2012 ability to boot reliably into macOS.
It's still possible to boot 11.3/11.4, but the process requires multiple restarts and a connection has been made between PCIe devices, especially storage related devices and USB controller cards, causing panics at boot. While most people report NVMe crashes, the issue is not NVMe related and PCIe SATA cards or AHCI PCIe M.2 devices, including Apple 12+16 AHCI PCIe models, also have the same crashes. It's probably an unknown race condition somewhere early in the kernel that is causing the crashes.
Some Mac Pros are less affected with the 11.3.1/11.4/11.5bx crashes and seems that having fewer PCIe devices installed improve the rate of successful boots. Other non-storage related PCIe devices also seem to contribute to the crashes like the older AirPort Extreme models - at this moment the best success rate of an AirPort Extreme model seems to be with the BCM943602CDPAX AirPort Extreme + bluetooth 4.1 combo card, but this card have unrelated issues when you boot Mojave from BigSur.
Please check if your NVRAM volume garbage collection is working before trying to test 11.3.1/11.4/11.5bx, if you have a Mac Pro with the VSS stores full, you could brick it with the constant crashes at boot - several people already have, be warned.
The crashes still continue to happen with the current 11.4 (20F71) release version and with the developers beta release, 11.5b2 (20G5033c).
To the users that do not have issues while booting 11.3, test at least 10 reboots before reporting successful then please list any PCIe cards, PCIe storage and the model of the AirPort Extreme you may have installed.
For detailed panic logs see here:
Note: MacPro4,1 and MacPro5,1 are not the only machines affected. These symptoms can be replicated less frequently by @khronokernel on MacPro3,1, iMac8,1, iMac11,2, MacBook7,1 and MacBookPro8,3 as well as by ASentientBot on a Penryn Hackintosh. Therefore this race condition is not limited by the CPU architecture and instead by the CPU's speed and number of PCI devices present for device setup
Big Sur 11.2.3 direct download from Apple servers: http://swcdn.apple.com/content/down...i7fezrmvu4vuab80m0e8a5ll/InstallAssistant.pkg
It's still possible to boot 11.3/11.4, but the process requires multiple restarts and a connection has been made between PCIe devices, especially storage related devices and USB controller cards, causing panics at boot. While most people report NVMe crashes, the issue is not NVMe related and PCIe SATA cards or AHCI PCIe M.2 devices, including Apple 12+16 AHCI PCIe models, also have the same crashes. It's probably an unknown race condition somewhere early in the kernel that is causing the crashes.
Some Mac Pros are less affected with the 11.3.1/11.4/11.5bx crashes and seems that having fewer PCIe devices installed improve the rate of successful boots. Other non-storage related PCIe devices also seem to contribute to the crashes like the older AirPort Extreme models - at this moment the best success rate of an AirPort Extreme model seems to be with the BCM943602CDPAX AirPort Extreme + bluetooth 4.1 combo card, but this card have unrelated issues when you boot Mojave from BigSur.
Please check if your NVRAM volume garbage collection is working before trying to test 11.3.1/11.4/11.5bx, if you have a Mac Pro with the VSS stores full, you could brick it with the constant crashes at boot - several people already have, be warned.
OpenCore on the Mac Pro
There is a extremely simple way (simple here as in not need to know how the NVRAM works/check free space indicators/validate checksums and etc) to check if the garbage collection failed and the need to reflash with the clean dump: Dump the BootROM with ROMTool Open the dump with the most...
forums.macrumors.com
The crashes still continue to happen with the current 11.4 (20F71) release version and with the developers beta release, 11.5b2 (20G5033c).
To the users that do not have issues while booting 11.3, test at least 10 reboots before reporting successful then please list any PCIe cards, PCIe storage and the model of the AirPort Extreme you may have installed.
For detailed panic logs see here:
Mac Pro 11.3 Beta NVME issues · Issue #110 · dortania/OpenCore-Legacy-Patcher
Describe the bug Im not sure this will fall within the scope of this patcher, Apple's changes in IONvmefamily has broken support with Mac Pros 5,1/4,1/3,1 the bug started with Beta 3 of 11.3 has co...
github.com
Note: MacPro4,1 and MacPro5,1 are not the only machines affected. These symptoms can be replicated less frequently by @khronokernel on MacPro3,1, iMac8,1, iMac11,2, MacBook7,1 and MacBookPro8,3 as well as by ASentientBot on a Penryn Hackintosh. Therefore this race condition is not limited by the CPU architecture and instead by the CPU's speed and number of PCI devices present for device setup
Big Sur 11.2.3 direct download link:
Big Sur 11.2.3 direct download from Apple servers: http://swcdn.apple.com/content/down...i7fezrmvu4vuab80m0e8a5ll/InstallAssistant.pkg
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