Right folks, Have decided to have a machine built only for Substance painter [ different machine from my Mcad machine ] the reasoning being, Substance has diferent needs from Mcad and am not a fan of "halfway house " compromise. hence the new machine. Prelim specs are as follows CPU Threadripper Pro 3955 WX, Cooling to be Noctua , Board Asus Pro WS WRX 80E Sage, Main and secondary drives Intel 750 series, Psu Corsair HX 1200 i Memory, 128 Gb Hyper X [ did initially think about ECC ram but that extra expense is not warranted ]. Gpu Nvidia RTX 3090 [ if the builder can get one !! ] Have always been an Intel guy so this will be my first machine using AMD [ any thoughts ] I could upgrade any / all components if needed ] as these specs are not set in stone yet .