it's not about ram nor graphic card, at least in my case. I turned graph settings to low and it didn't work better at all still got like 1 fps there. It is caused by sound settings - high (128 channels), if you set that lower (to 64/32) it should work fine. It works fine (pretty much no fps drop there) for me at least.
Even though my sound card supports 128 channels (asus xonar d1) it looks like the game does not recognize that, so it overloads cpu with sound processing -> huge fps drop.