Window 11 Known Issues And How To Install Them
We Don’t Need No Stinkin’ TPM 2.0 … AKA MoSetup, MoProblems
If you like to live dangerously you can pop into your registry and create a DWORD called “AllowUpgradesWithUnsupportedTPMOrCPU” under HKEY_LOCAL_MACHINE\SYSTEM\Setup\MoSetup and set it to a value of 1. After doing so you can then successfully run the Media Creation Tool and even mount the resulting ISO to your PC and upgrade in place. That lets you bypass the unsupported CPU error as well as leaving TPM 2.0 off; be aware you still need TPM 1.4 as that seems to be an actual hardware requirement.
Sadly, the list of unsupported CPUs does not list all AMD processors, as it turns out that Windows 11 and AMD’s L3 cache architecture do not play nicely. AMD have reported that their customers can expect to see a threefold increase in functional L3 cache latency, which will definitely have an impact on general performance. The issue gets worse the better your processor, with CPUs that slurp more than 65W and sport more than eight cores being impacted more severely than lower powered processors.
It is not just AMD that takes a performance hit, Intel’s Killer NICs and their SmartByte networking software are both seeing noticeable drops in bandwidth on machines running Windows 11. There is also a serious compatibility problem with Oracle VirtualBox, to the point where you will be unable to even start your VMs. Whatever you do, don’t load an Oracle instance on an Threadripper system which uses a Killer NIC!
Patches are expected for these later this month, and with Windows 11 only being available for 2 days so far you can expect the list to grow before it shrinks.
A software update is in development to address this issue with expected availability in October of 2021.