It is actually not, I was wrong. It is an internal limitation on the bus that limits it to about 400 Mbps by default, some people have been able to squeeze a li

It is actually not, I was wrong. It is an internal limitation on the bus that limits it to about 400 Mbps by default, some people have been able to squeeze a little more out of it. After that point though all kinds of issues start appearing. See the links provided in the discussion below.