Connect ports 5 and 6 with a short cable
Actually, I had wondered about this myself.
I guess you can't get much closer to "wirespeed" than an actual wire, eh?
Of course it doesn't get actual wirespeed. When you would have a single 10-port switch you could have a 1 Gbps
transfer between port 1 and 10, and another one between 2 and 9, and another one between 3 and 8, all at the
same time. But with this solution you can have only 1 Gbps between the lower and the higher port group.
Indeed it could well be that the bridged solution outperforms this, because the link between the switch and CPU
is 2.5 Mbps and so is faster than each port.
The advantage of the wire method is that it does not load the CPU. Not that it is wirespeed.