New results (user time only, removing read() overhead):
OpenSSL: 6.8s or 9.8s = 147 or 102 MB/s = 1176 or 816 Mbit/s
Nettle: 8.8s or 11.8s = 113 MB/s or 85 MB/s = 904 or 680 Mbit/s
APT: 10.9s or 15s = 92 MB/s or 67 MB/s = 736 or 536 Mbit/s
As we can see, the improvement is not that large, and libnettle also still has a small way to go to reach OpenSSL's performance.
New results (user time only, removing read() overhead):
OpenSSL: 6.8s or 9.8s = 147 or 102 MB/s = 1176 or 816 Mbit/s
Nettle: 8.8s or 11.8s = 113 MB/s or 85 MB/s = 904 or 680 Mbit/s
APT: 10.9s or 15s = 92 MB/s or 67 MB/s = 736 or 536 Mbit/s
As we can see, the improvement is not that large, and libnettle also still has a small way to go to reach OpenSSL's performance.