NFS Speed on local interfaces?

Say I have a server with NFS shares exported on a ethernet interface. If local VM's, jailed services, etc access these shares, is their connection speed limited in any way by the speed of the underlying interface?

For example if the exported shares are bound to an IP on a gigabit NIC, are local services who access these shares limited to 1Gbps? Or do they get full throughput of the disks because they are in essence on a local loopback?

Sorry if it's a silly question, but I haven't been able to find the answer anywhere.

I'm trying to setup a VM and a few jails on a server, with shared access to a common storage pool. The jails I can easily give access to the data via nullfs, but it seems like the best way to give a VM access is through NFS. However, if the NFS performance is limited to the speed of the emulated network interface, I'd like to find a different solution as the data pool is capable of transferring 2+ GB/s and I'd like to take advantage of that.