Forum Discussion
Alder Lake 12th Gen Intel CPU won't boot on Windows Server 2022 with HyperV enabled
My PC has 12700K, ASUS Z690 mainboard, 64GB DDR5, and Samsung 980Pro. I'm trying to run Windows Server 2022 on it, but it will not boot when I enabled Hyper-V. It will boot fine without Hyper-V role...
I'm not sure if it's related, but Alder Lake doesn't appear to support RSS when Hyper-V features are enabled, at least on Intel's I225 NIC. I have a long thread on Intel's forum where they ultimately blamed MS for the issue (even though Intel's NetAdapter NIC drivers don't appear to properly disabled RSS before the driver is initialized if RSS was previously enabled).
At any rate, this can be tested by disabling RSS via PowerShell on your physical network adapter(s):
get-netadapter
(to get the name of your physical NIC(s), mine was just "ethernet")
disable-netadapterrss -name ethernet
(where "name" is the name of your physical NIC)
After this, try to re-enable your E-Cores and see if your system boots properly. If it does boot, you can likely re-enable RSS but restrict to the P-cores. A 12700K has 8 P-cores, which will be processor 0-14 if hyperthreading is enabled (RSS automatically ignores HT cores). Disable E-Cores from your BIOS again to be safe and then run the following via PowerShell:
enable-netadapterrss -name ethernet
set-netadapterrss -name ethernet -maxprocessornumber 14
set-netadapterrss -name ethernet -maxprocessors 4
(again, where "name" is the name of your physical NIC)
Reboot, enable E-Cores in the BIOS, and you should be back up and running with RSS enabled. I am not running Hyper-V, but I'm running Windows 11 with WSL and WSB enabled, both of which use Hyper-V's networking stack. I was getting BSOD's after updating my NIC drivers, which led down the rabbit hole where I finally discovered the above solution. Hopefully this lets you use Hyper-V with E-Cores enabled!
The ultimate solution is likely MS automatically disabling E-Cores for RSS, the same way it automatically disables HT cores.
At any rate, this can be tested by disabling RSS via PowerShell on your physical network adapter(s):
get-netadapter
(to get the name of your physical NIC(s), mine was just "ethernet")
disable-netadapterrss -name ethernet
(where "name" is the name of your physical NIC)
After this, try to re-enable your E-Cores and see if your system boots properly. If it does boot, you can likely re-enable RSS but restrict to the P-cores. A 12700K has 8 P-cores, which will be processor 0-14 if hyperthreading is enabled (RSS automatically ignores HT cores). Disable E-Cores from your BIOS again to be safe and then run the following via PowerShell:
enable-netadapterrss -name ethernet
set-netadapterrss -name ethernet -maxprocessornumber 14
set-netadapterrss -name ethernet -maxprocessors 4
(again, where "name" is the name of your physical NIC)
Reboot, enable E-Cores in the BIOS, and you should be back up and running with RSS enabled. I am not running Hyper-V, but I'm running Windows 11 with WSL and WSB enabled, both of which use Hyper-V's networking stack. I was getting BSOD's after updating my NIC drivers, which led down the rabbit hole where I finally discovered the above solution. Hopefully this lets you use Hyper-V with E-Cores enabled!
The ultimate solution is likely MS automatically disabling E-Cores for RSS, the same way it automatically disables HT cores.
- Eight months have gone by. Has this been fixed by Microsoft? I still have all efficiency cores disabled because of this.
The PC I would like to use as a lab & test - Lenovo M90q Gen3 with i7-12700 does not even have the possibility to turn off efficiency cores in the BIOS, so I am stuck with a great machine with 64 GB fast DDR5 RAM and no chance to use Hyper-V, which is a real bummer. Wish there were some information on whether any updates to Windows 2022 will address the problem...
Ronny Röe The only option on running a VM, is use Windows 11. Enable the Hyper-v feature.
In Windows 11 you can use all Cores there is no need to disable the cores. But Windows 11 is not Windows Server 2022.
