Sea Demon, in terms of your slow loading times, and what I call "Ram unloading" while you wait for the desktop to return, yes, that's directly and specifically related to the RAM. More Ram would speed that up.
But specifically to playing SH4, I do fine with 1 gig. Maerean_m's post above maybe correct about the 1.3 G Ram, but my game does play fine. It takes me a moment as well to go from inside to outside while the exterior textures load, but it's not a game killer for me.
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