"I currently have that Rage3d.com link open in another tab atm . I never said that that sideport was not part of the chip, just that there has been this sideport on the chip since the X1950Pro. This CrossFireX sideport is connected to the hub this time around and it apparently is a 'relatively low bandwidth interconnect'."
Do you have a link for the rv670 block diagram with crossfire side port shown on it? i can't find one. Please share your source diagram... Ditto for x1950xt... no Crossfire side port connected to the memory bus / hub seen there either.
http://www.google.ca/imgres?imgurl=h...&ct=image&cd=1
The physical connectors on the card, are not what we mean when we say Crossfire X side port... In this case it seems to be something worthy enough of note that it is now included on the block diagram for RV770, and does not appear on the Ringbus diagram for r600, nor any block diagram I can find for rv670... Notice in particular the Ring Bus diagram for R600 - this shows the ring stop for PCIe, which is now located attached to the new hub on rv770... The Crossfire X side port is also connected to this hub. So how does that equate to Cross Fire X side port being low bandwidth? (can see relatively low bandwidth as in less then GDDR5 throughput, even PCIE 2.0 x16 is relatively lower bandwidth then that, granted) As well, if it was present on R600, why is it absent from all the diagrams?
http://www.ixbt.com/video3/images/r600/diag_ringbus.png
http://hothardware.com/Articles/ATI_...rrived/?page=2