All my servers with PVE kernel enabled show poor outgoing connections performance:
ab -n 10000 -c 1000 example.url
4.4.21-1-pve
Requests per second: 679.38
4.4.35-1-pve
Requests per second: 754.42
4.13.13-5-pve
Requests per second: 692.04
4.13.13-6-pve
Requests per second...