I have 24 GB ram, page file disabled to use the RAM efficiently with W7/64. PC is a I7 with SSD and raid.
Although I have limited Premiere to leave 8 GB for other applications it uses very quickly more than 23 GB and more or less crashes the PC! Loading a project with about 2 h of clips takes ore than 5 minutes while the performance monitor shows nearly no activity (processor and HDD): What a crap! and idea to solve this problem. For me the program is not usable.