Is pcie revision 2 needed to mine?

[underminer]

What is pcie revision good for for miners?  Nothing?

I've been told that pcie rev 2 is needed to mine, but this flies in the face of what I've read and what I've done with my systems...  We use extenders to chop card bandwidth all the time with no detriment... How is this any different unless it has to do with specific card / mobo compatibility.