Results without background task: 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 15.8615 s, 2.1 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 15.6571 s, 2.1 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 15.837 s, 2.1 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 7.69644 s, 4.4 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 7.92178 s, 4.2 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 7.48486 s, 4.5 MB/s Results with ping -i.01 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 7.84103 s, 4.3 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 8.1514 s, 4.1 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 7.89728 s, 4.2 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.6673 s, 9.1 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.81842 s, 8.8 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.73419 s, 9.0 MB/s PING localhost (127.0.0.1) 56(84) bytes of data. --- localhost ping statistics --- 2249 packets transmitted, 2249 received, 0% packet loss, time 35138ms rtt min/avg/max/mdev = 0.000/0.024/0.091/0.016 ms Results with ping -i.0099 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 5.17194 s, 6.5 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 5.9747 s, 5.6 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.85498 s, 8.7 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 1.93466 s, 17.3 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 2.72922 s, 12.3 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 2.78073 s, 12.1 MB/s PING localhost (127.0.0.1) 56(84) bytes of data. --- localhost ping statistics --- 2500 packets transmitted, 2500 received, 0% packet loss, time 22480ms rtt min/avg/max/mdev = 0.000/0.001/0.153/0.006 ms Results with perl busy loop 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 5.20282 s, 6.4 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.7533 s, 8.9 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.46155 s, 9.7 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.48111 s, 9.6 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.08258 s, 10.9 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.67957 s, 9.1 MB/s ./speedtest.sh: line 29: 1067 Terminated perl -e "while (1) { }" Results with perl usleep(1) 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.01886 s, 11.1 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.01447 s, 11.1 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 3.04059 s, 11.0 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 2.13828 s, 15.7 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 2.11844 s, 15.8 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 2.08154 s, 16.1 MB/s ./speedtest.sh: line 35: 1076 Terminated perl -e "use Time::HiRes qw( usleep ); while (1) { usleep(1) }" Results with perl yield 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 5.09384 s, 6.6 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 7.06738 s, 4.7 MB/s 512+0 records in 512+0 records out 33554432 bytes (34 MB) copied, 4.4223 s, 7.6 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.54556 s, 9.5 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.7247 s, 9.0 MB/s 32+0 records in 32+0 records out 33554432 bytes (34 MB) copied, 3.74228 s, 9.0 MB/s ./speedtest.sh: line 41: 1084 Terminated perl -e "use Thread qw( yield ); while (1) { yield }"