250mb/s connection speed, yet only achieving 95mb/s on the new rig.
It seems you're unsure about the issue and want confirmation. Could you provide the switch model for a more accurate response?
Netgear Prosafe 8-Port Gigabit Switch Model GS108
It must be the wire, since simply plugging into the outlet only provides up to 94MB/s no matter if a switch is present or not.
Seems like the wire might be the issue.