I run 2 wordpress sites that receive about 50k hits in total a day. They both have w3total cache enabled. I noticed my vps has a slightly high cpu load. This is what top looks like:
top - 21:03:44 up 4 days, 3:52, 1 user, load average: 5.06, 4.56, 4.51
Tasks: 63 total, 1 running, 62 sleeping, 0 stopped, 0 zombie
%Cpu(s): 18.1 us, 3.1 sy, 0.0 ni, 75.6 id, 2.8 wa, 0.0 hi, 0.4 si, 0.0 st
KiB Mem: 8388608 total, 8273624 used, 114984 free, 0 buffers
KiB Swap: 524288 total, 0 used, 524288 free. 6963472 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
12721 www-data 20 0 477500 102560 80252 S 17.6 1.2 0:55.07 php-fpm5.6
12483 www-data 20 0 503648 129632 81156 S 12.6 1.5 1:35.04 php-fpm5.6
12385 www-data 20 0 495632 121840 81604 S 9.0 1.5 2:08.49 php-fpm5.6
12441 www-data 20 0 483256 109616 81580 S 4.0 1.3 1:39.73 php-fpm5.6
12464 www-data 20 0 484512 110512 81192 S 3.3 1.3 1:39.07 php-fpm5.6
2055 mysql 20 0 2141564 556228 14552 S 1.0 6.6 594:45.21 mysqld
2235 memcache 20 0 394844 78580 2336 S 0.7 0.9 140:48.05 memcached
12729 www-data 20 0 478332 103392 80252 S 0.7 1.2 0:56.09 php-fpm5.6
2069 www-data 20 0 214944 13928 5396 S 0.3 0.2 1:30.97 nginx
2074 www-data 20 0 214944 13596 5396 S 0.3 0.2 1:25.78 nginx
12485 www-data 20 0 479620 105700 81272 S 0.3 1.3 1:25.96 php-fpm5.6
1 root 20 0 33120 3092 2156 S 0.0 0.0 0:00.54 init
478 root 20 0 19480 176 0 S 0.0 0.0 0:00.03 upstart-udev-br
617 root 20 0 49268 2916 2496 S 0.0 0.0 0:02.95 systemd-udevd
730 root 20 0 15524 1820 1308 S 0.0 0.0 0:00.03 upstart-socket-
1060 root 20 0 15280 204 0 S 0.0 0.0 0:00.01 upstart-file-br
1390 syslog 20 0 180044 4960 2176 S 0.0 0.1 0:00.72 rsyslogd
1681 root 20 0 23656 2284 2028 S 0.0 0.0 0:00.41 cron
1689 root 20 0 387844 35372 27676 S 0.0 0.4 0:32.67 php-fpm5.6
1789 root 20 0 61384 5300 4624 S 0.0 0.1 0:00.58 sshd
1845 root 20 0 18224 3248 2744 S 0.0 0.0 0:00.02 mysqld_safe
2056 root 20 0 4344 1588 1484 S 0.0 0.0 0:00.00 logger
2068 root 20 0 210848 6200 1648 S 0.0 0.1 0:00.01 nginx
2071 www-data 20 0 216992 15976 5392 S 0.0 0.2 1:33.71 nginx
2072 www-data 20 0 214944 13788 5392 S 0.0 0.2 1:27.90 nginx
2073 www-data 20 0 214944 14052 5396 S 0.0 0.2 1:26.75 nginx
2075 www-data 20 0 213920 13120 5396 S 0.0 0.2 1:27.46 nginx
2076 www-data 20 0 214944 13860 5396 S 0.0 0.2 1:29.46 nginx
2077 www-data 20 0 215968 14920 5392 S 0.0 0.2 1:27.25 nginx
2078 www-data 20 0 214944 13780 5396 S 0.0 0.2 1:32.38 nginx
2079 www-data 20 0 214944 13548 5392 S 0.0 0.2 1:30.17 nginx
2080 www-data 20 0 215968 14724 5164 S 0.0 0.2 1:31.07 nginx
2081 www-data 20 0 216992 15712 5200 S 0.0 0.2 1:28.56 nginx
2082 www-data 20 0 214944 13692 5260 S 0.0 0.2 1:26.82 nginx
2083 www-data 20 0 214944 14084 5292 S 0.0 0.2 1:29.20 nginx
2084 www-data 20 0 213920 12612 5396 S 0.0 0.2 1:26.95 nginx
2085 www-data 20 0 213920 13364 5396 S 0.0 0.2 1:30.72 nginx
2086 www-data 20 0 215968 14636 5388 S 0.0 0.2 1:26.73 nginx
2087 www-data 20 0 215968 14888 5396 S 0.0 0.2 1:31.11 nginx
2088 www-data 20 0 214944 14232 5396 S 0.0 0.2 1:29.50 nginx
2089 www-data 20 0 215968 15104 5396 S 0.0 0.2 1:30.13 nginx
2090 www-data 20 0 214944 13864 5396 S 0.0 0.2 1:34.87 nginx
2091 www-data 20 0 214944 13724 5388 S 0.0 0.2 1:29.85 nginx
2092 www-data 20 0 214944 14232 5396 S 0.0 0.2 1:22.95 nginx
2093 www-data 20 0 213920 13108 5396 S 0.0 0.2 1:32.29 nginx
2094 www-data 20 0 210848 7268 2504 S 0.0 0.1 0:01.43 nginx
2402 root 20 0 25344 2960 2640 S 0.0 0.0 0:01.65 master
2414 postfix 20 0 27576 2924 2580 S 0.0 0.0 0:00.18 qmgr
2440 root 20 0 560504 11236 3840 S 0.0 0.1 8:58.39 fail2ban-server
2489 root 20 0 12788 1940 1796 S 0.0 0.0 0:00.00 getty
2491 root 20 0 12788 1876 1724 S 0.0 0.0 0:00.00 getty
2492 root 20 0 12788 1900 1756 S 0.0 0.0 0:00.00 getty
2605 postfix 20 0 40180 5244 4696 S 0.0 0.1 0:00.21 tlsmgr
11671 postfix 20 0 27408 2916 2636 S 0.0 0.0 0:00.00 pickup
12351 www-data 20 0 487088 112680 81144 S 0.0 1.3 2:08.05 php-fpm5.6
12360 www-data 20 0 487332 115156 83020 S 0.0 1.4 2:03.74 php-fpm5.6
The high cpu load seems to be coming from php-fpm. Does anyone know how can I reduce it? my vps has 8gb ram & 4 cpu of Intel® Xeon® CPU X5650 @ 2.67GHz