suggest the server specs

Hello

my server will host around 5 wordpress websites with medium traffic (maybe low/very low for some websites)

-what is the suggested server specs

-Im using

varnish
Memcached
APCU
hugepage php7.1

---

-currently I'm on:

Code (Text):

 - CPU usage.....: 0.06, 0.05, 0.05 (1, 5, 15 min)
 - Processes.....: 114 running
 - System uptime.: 5 days 6 hours 31 minutes 39 seconds
===============================================================================
              total        used        free      shared  buff/cache   available
Mem:           3700        1047         624         274        2027        2056
Swap:          1023           5        1018
===============================================================================
Filesystem     Type      Size  Used Avail Use% Mounted on
/dev/sda1      xfs        30G   14G   17G  44% /
devtmpfs       devtmpfs  1.9G     0  1.9G   0% /dev
tmpfs          tmpfs     1.9G     0  1.9G   0% /dev/shm
tmpfs          tmpfs     1.9G  179M  1.7G  10% /run
tmpfs          tmpfs     1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs          tmpfs     371M     0  371M   0% /run/user/0
tmpfs          tmpfs     371M     0  371M   0% /run/user/1001