So I was playing for a couple hours and man did those menu screens get really, really laggy. I quit the game and played on low settings and it ran fine then played with high settings and it still ran fine. Setting VRAM to max made it rather jittery though.
Anyway, I was getting very laggy menu screens with fullscreen/high graphics/normal VRAM, although now I cannot reproduce it. Maybe it only stutters after long playtime or maybe I just had an unlucky session.
This. I have the same exact problem. Menus and dialogue boxes become so laggy the game becomes next to unplayable. I have to press Z, X, or C 15 or 20 times before the game will move onto the next one or two sentence chunk of dialogue. Trying to navigate menus and equip something can easily take 2 or 3 minutes.
I can reproduce it though. Playing on high graphics and normal VRAM. It happens in windowed or full screen mode. It works fine at first but then as the game goes on the menus start to go at a crawl.
I have AMD Dual Core Processor 3.0 GHz, 8 gigs of ram, with a NVIDIA GeForce 8800 GT on Vista 64 bit. It's not the most powerful machine but I can play Shogun 2 on high at 30 to 40 fps.