Network packet size on sql server connection string to improve throughput

What needs to happen is that the MTU setting on the ethernet network needs to be increased from 1500 to something north of 4096. These settings are typically set on the Driver settings page. For good networking you really want all devices (including all ethernet switches) on the same ethernet to have the same MTU setting.

_{(source: sysadmin1138.net)}

That's where you'd change it on one of my servers.

Can it help? It certainly can. Less packet fragmentation means less work on the TCP stack to reassemble the traffic stream. It may not be orders of magnitude, but it could help.

Connections local to the server use, I believe, pipes rather than TCP connections and are probably unaffected by this change.

You can try, but I doubt it will help much. TDS as a protocol was never designed for high troughput. If you want to move data between two SQL server instances you may consider using Service Broker instead, its network stack is much more oriented toward high troughput than the TDS one. This is why Mirroring choose the SSB network stack to communicate with the standby mirror servers. Besides the data movement semantics of SSB are much better than linked servers and usually better than custom client apps.

I can't comment on tcp, frames etc, but I've only set SQL Sever network packet size once, ever, for some vile app that still needed SQL 6.5 client tools.

It's one of those "don't do it" settings.