The advantage of hardware random number generators are:
Higher security level
Better random numbers
Faster
The following might show no difference since modern kernels mix all different (and there are many) number generators to feed /dev/random
Modern kernels have a random number generator entropy pool
In the age of cyber security, hardware random generators became a standard
CPU's, Network interfaces, TPM security chips contain hardware random number generators and can be enabled in the kernel. Dedicated hardware might be available and be accessed via a kernel module as intel-rng
. This produces /dev/hwrng
For Gentoo Linux emerge rng-tools this gives programs as rngtest , randstat and the configuration file /etc/conf.d/rngd
rngd -dt is a first test to see if the user space daemon is happy
Start the service /etc/init.d/rngd restart
cat /dev/random | rngtest -c 1000 or rngtest -c 100 < /dev/hwrng is how rngtest is used
dd if=/dev/random of=/dev/null bs=1024 count=1 iflag=fullblock should return immediately if there is one of the many hardware random number generators
randstat is a program that returns the same as cat /proc/sys/kernel/random/entropy_avail
Add it to boot service rc-update add rngd boot
An other test is cat /dev/hwrng or with or without hardware random number generator cat /dev/random or cat /dev/urandom to stop Ctrl+C