*Corrected mistake, thanks Martin.
I have previously posted about memory usage on 7.10.
All tests were done with an Ubuntu LiveCD on the same machine for both 7.10 and 8.04.1. A network card may have changed between 7.10 and 8.04.1. Applications used were Firefox, OpenOffice.org Writer, Rhythmbox, Totem and Gimp. All values copied out of Gnome System Monitor.
Comparing Ubuntu 8.04.1 64 to 32
|32 bit||64 bit||Difference|
|With Apps Open||262.7||395.7||133|
Note: This was a very very small test.
Comparing 7.10 to 8.04.1, Initial Boot Only