While the NX11 System Requirement guidelines do discuss Processor Performance, SMP and Multi-Core, there is nothing that suggests that a specific processor is required. I'd be interested to know where you got that information.
I think the new requirement is SSSE3 instructions support. You need a intel Core 2 or a AMD bobcat any processor older than than won't run NX11 but this are quite old processor, it is not likely to still work with older machines.
That information can be found in the Hardware Certification tables. The last tab on the spreadsheet "Caveats" explains that older x64 processors are not supported: "Older Intel and AMD processors that do not support SSSE3 instructions are not supported by NX11. NX tests the instruction set and raises an error on older processors. These instructions were introduced in 2006 and pervasive by 2008".
I tried to install NX11 on my personal laptop. I've run 9 and 10 on it no problem. Sometimes I've had to take my job into the woods...
NX11 installs but wont run. Says unsupported processor
It's an AMD Phenon II 850
Elmhirst Industries, Specializing in Prototype sheet metal stampings and assemblies
Production: NX 12.0.1 / Autoform r7 /WorkNC 2018 r2
PC: Rave Cadbeast: Intel(R) i7-4790K CPU @ 4.GHz /32gb ram /NVIDIA Quadro P2000 on Win10 Pro