Dolphin stuttering and Ubershaders

[71knight]

Does it matter how many shader cores a gpu has when using ubershaders?  Can a small amount of shader cores cause stuttering?  I know nvidia's shaders are generally twice as powerful as amd's.  What amount would you recommend?  Also I saw this post --- "Metroid Prime overflows the JIT cache due to dynamic code generation. If you see stutters on synchronous ubershaders when you can easily run it full speed with no frame limiter, that's the remaining cause."---  Does this mean you can't ever get rid of stuttering in some games?