I have a webserver with a current connection of 100Mbit and my provider offers an upgrade to 1Gbit. I understand that this refers to throughput but the larger the packets, the faster they can be transmitted as well, so I would expect a slight decrease in response time (e.g. ping). Did anybody ever benchmarked this?
Example (100mbit to 100mbit server) with 30 byte load:
> ping server -i0.05 -c200 -s30
[...]
200 packets transmitted, 200 received, 0% packet loss, time 9948ms
rtt min/avg/max/mdev = 0.093/0.164/0.960/0.093 ms
Example (100mbit to 100mbit server) with 300 byte load (which is below MTU):
> ping server -i0.05 -c200 -s300
[...]
200 packets transmitted, 200 received, 0% packet loss, time 10037ms
rtt min/avg/max/mdev = 0.235/0.395/0.841/0.078 ms
So from 30 to 300 the avg. latency increaces from 0.164 to 0.395 – I would expect this to be a slower increase for a 1gibt to 1gbit connection. I even would expect 100mbit to 1gbit to be faster, if the connection is through a switch which first waits until it received the whole packet.
Update: Please read the comments to the answers carefully! The connection is not saturated, and I don't think that this speed increase will matter for humans for one request, but it is about many requests which add up (Redis, Database, etc.).
Regarding answer from @LatinSuD:
> ping server -i0.05 -c200 -s1400
200 packets transmitted, 200 received, 0% packet loss, time 9958ms
rtt min/avg/max/mdev = 0.662/0.866/1.557/0.110 ms
Best Answer
The only way latency would drop appreciably is if the current 100Mbit link is saturated. If it is not saturated, you will likely not notice any change.
Additionally, your assumption that the 1Gbit link will be able to support larger packets is incorrect. Max packet size is determined by the MTU of the various devices along the path that the packet takes - starting with the NIC on your server, all the way through to the MTU of your customer's computer. In internal LAN applications (when you have control over all the devices along the path), it is sometimes possible to increase the MTU, but in this situation, you are pretty much stuck with the default MTU of 1500. If you send packets larger than that, they will end up getting fragmented, thereby actually decreasing performance.