H11DSi / H11DSi-NT User's Manual
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Question: Why did the system freeze and fail to begin installation when I tried to install
Windows Server 2016?
Answer: Windows Sever 2016 support is limited to less than 255 logical processors, and it
does not support x2APIC. Follow the steps to solve the problem.
1. Disable SMT in BIOS. (BIOS >> Advanced >> CPU Conguration >> SMT Control
>>Disabled)
2. Set the option of Local APIC Mode to be xAPIC in BIOS. (BIOS >> Advanced >>
CPUConguration >> Local APIC Mode >> xAPIC)
3. Install Windows Server 2016 again.
Question: Why did I fail to install Windows Server 2019 on a system with more than
255 logical processors?
Answer: Follow the steps to solve the problem.
1. Disable SMT in BIOS. (BIOS >> Advanced >> CPU Conguration >> SMT Control
>>Disabled)
2. Enable IOMMU in BIOS. (BIOS>>Advanced>>NB Conguration >>IOMMU>>Enable)
3. Install Windows Server 2019.
4. Install any required updates to ensure your installed Windows Server 2019 is up to date.
5. Ensure patch KB4512534 is now installed, reboot the system, and anter the BIOS setup
utility.
6. Set the option of Local APIC Mode to be x2APIC in BIOS. (BIOS >> Advanced >> CPU
Conguration >> Local APIC Mode >> x2APIC)
7. Enable SMP in BIOS. (BIOS >> Advanced >> CPU Conguration >> SMT Control >>
Enabled)
8. All logical cores are available for use.
Question: Why are not all 256 CPU cores displayed on Linux?
Answer: This issue is due to that your Linux kernel does not support 256 CPU cores. Make
sure that your Linux kernel version is equal to or higher than 4.19x, and enable IOMMU (Input/
Output Memory Management Unit) in BIOS.