I ran some tests with Ryzen 1800X and Asus Crosshair VI Hero board and it seems like enabling SVM in bios causes CPU to NOT be able to do 1 and 2 core boost.
With SVM disabled CPU easily holds 4.1 GHz when 1 core is under load (Cinebench single threaded). Enabling SVM the CPU goes only up to 3.6-3.7 GHz with extremely sporadic spikes to 4.1GHz.
Is this expected behavior? I wouldn't expect SVM to affect clocks (at least not if it's not in use -- just enabled).
Here it's the same wiith 1700X...with SVM disabled boost is much more frequent!!!...Nice!!..So probably it's normal.......i have no idea why...but i remember that with another CPU (i7 3930K) enabling virtualization and hypervisor, performance in windows dropped significantly (-3/5% in bench, and cpu turbo not so frequent), without using any virtual machine, but only for having enabled that feature....it seems that Windows is reserving or loading CPU resources...even if you are not using any virtual machine....probably some hidden service in windows...or something at kernel level...
it's an interesting question...And nice discovery! i've never noticed this thing because i've always enabled that feature (SVM) in bios, even if it's disabled at default.