[michael@s1 ~]$ dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 2,16283 s, 496 MB/s
[michael@s1 ~]$ dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 2,78887 s, 385 MB/s
[michael@s1 ~]$ dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 3,2345 s, 332 MB/s
[michael@s1 ~]$ dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 1,0517 s, 1,0 GB/s
[michael@s1 ~]$ echo 3 | sudo tee /proc/sys/vm/drop_caches
3
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 5,33917 s, 201 MB/s
[michael@s1 ~]$ echo 3 | sudo tee /proc/sys/vm/drop_caches
3
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 4,18779 s, 256 MB/s
[michael@s1 ~]$ echo 3 | sudo tee /proc/sys/vm/drop_caches
3
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 4,30678 s, 249 MB/s
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 0,354806 s, 3,0 GB/s
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 0,288564 s, 3,7 GB/s
[michael@s1 ~]$ dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 0,306819 s, 3,5 GB/s