Before:

total       used       free     shared    buffers     cached
Mem:        515792     509452       6340          0       3312     276876
-/+ buffers/cache:     229264     286528
Swap:      1052248        320    1051928

After:

total       used       free     shared    buffers     cached
Mem:       1556108     526080    1030028          0      30640     344104
-/+ buffers/cache:     151336    1404772
Swap:      1052248          0    1052248