% memuse                                                                                                              [~]
177 MB     /usr/lib/chromium/chromium
115     /usr/lib/chromium/chromium
76      java
69      /usr/lib/chromium/chromium
54      /usr/lib/chromium/chromium
33      ffplay
32      /usr/lib/chromium/chromium
31      /usr/lib/mozc/mozc_server
31      /usr/lib/chromium/chromium
21      /usr/bin/Xorg.bin
16      xfe
13      uim-toolbar-gtk
11      xterm
11      uim-xim
11      /usr/lib/uim/uim-candwin-gtk
11      /usr/lib/chromium/chromium
10      ruby
10      fvwm2
10      /usr/lib/fvwm/2.6.5/FvwmTaskBar
8       ruby

これで300MBくらいだな(;´Д`)
1GB必要になることはあんまりない