In one window:
$ ./mem 12000 <<-- time 1
allocating 12582912000 bytes (12000.00 MB)
number of integers in array: 3145728000
loop 0 in 5604.98 ms (bandwidth: 2140.95 MB/s)
loop 1 in 2092.22 ms (bandwidth: 5735.54 MB/s)
loop 2 in 2088.83 ms (bandwidth: 5744.85 MB/s)
loop 3 in 2103.87 ms (bandwidth: 5703.77 MB/s)
^C <<-- time 2
$
In another window:
$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
1 0 827184 8436620 4084564 2224596 0 2 118 61 3 4 1 1 97 0 0
0 0 827184 8436496 4084564 2224596 0 0 0 0 181 534 1 0 99 0 0
0 0 827184 8436364 4084564 2224588 0 0 0 0 307 1054 2 1 96 0 0
1 0 827184 8441324 4084564 2219468 0 0 0 0 318 1452 4 1 96 0 0
1 0 827184 7307468 4084564 2224956 0 0 0 127 380 991 8 7 85 0 0 <<-- time 1
1 0 827184 5073352 4084564 2225108 0 0 0 0 459 773 14 12 74 0 0
1 0 827184 2856232 4084564 2224596 0 0 0 0 468 503 14 12 74 0 0
1 0 827184 616916 4084564 2224596 0 0 0 0 463 467 15 11 74 0 0
2 0 827184 165356 3384604 1191244 0 40 0 43 798 1245 13 20 66 0 0
2 0 838704 153824 1897456 534920 0 11480 168 11516 1045 1368 13 25 62 0 0
1 0 840496 258872 1662480 511156 0 1716 794 1717 700 952 25 4 71 1 0
1 0 840496 258624 1662500 511664 0 0 264 0 458 499 26 0 74 0 0
1 0 840496 258624 1662632 511664 0 0 132 0 469 468 25 0 74 0 0
1 0 840496 258624 1662632 511664 0 0 0 0 439 504 25 0 74 0 0
1 0 840496 10478440 1662632 513316 0 0 1652 0 490 817 17 9 74 0 0 <<-- time 2
0 0 840496 12568236 1662632 513384 0 0 60 0 253 609 0 3 97 0 0
0 0 840496 12573568 1662632 507976 0 0 0 3 183 570 1 0 99 0 0
0 0 840496 12568112 1662632 513268 0 0 0 0 245 980 2 1 98 0 0
^C
$