That should be feasible even with emulation. My memory seems to be a bit faulty, but IIRC UltraHLE could run SM64 at full speed on systems with less than 1GB and 1Ghz.
I can't remember if it was full speed but it was perfectly playable to emulate SM64 with UltraHLE on my Pentium 200MMX OC to 225MHz with a Voodoo 2 8MB and 96MB of RAM.
I had to run it in Windows NT5 beta though, it stuttered in Windows 95.