The rate of "entropy creation" on my system (Linux 4.13.0-38-generic, 16.04.1-Ubuntu, Intel® Celeron(R) CPU G3930 @ 2.90GHz × 2, main disk is SSD) is an impractically slow much less than 1 bit per second.
Note: I judge the rate of entropy creation using this command:
watch -n1 cat /proc/sys/kernel/random/entropy_avail
On the other hand, the underlying Linux CSPRNG is producing data at a good pace of about 187 Mb per second:
$ dd if=/dev/urandom of=/dev/null bs=1M count=1024 iflag=fullblock 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB, 1.0 GiB) copied, 5.74347 s, 187 MB/s
rng-tools. It is working and reading
/dev/hwrng as expected:
% systemctl status rng-tools ● rng-tools.service Loaded: loaded (/etc/init.d/rng-tools; bad; vendor preset: enabled) Active: active (running) since Sat 2018-04-28 13:17:17 PDT; 33s ago Docs: man:systemd-sysv-generator(8) Process: 15840 ExecStop=/etc/init.d/rng-tools stop (code=exited, status=0/SUCC Process: 23876 ExecStart=/etc/init.d/rng-tools start (code=exited, status=0/SU CGroup: /system.slice/rng-tools.service └─23878 /usr/sbin/rngd -r /dev/hwrng
However, the entropy rate is barely changed, and still is far less than 1 bit per second.
The hardware RNG is presumably creating much more than 1 bit per second. So why does the rate of entropy creation not increase significantly?