likely its not that removing it had not performance penalty, but keeping it , did hurt performance.
maybe they found the low latency, low bandwhich crossfire link was harming performance. unless they create a 16x pci-e on the top for the crossfire , it doesn't actually make any sense
now that they're trying to prevent lag, micro stuttering. if you have a lower latency bus for crossfire. you introduce a calculation differential .
does 1x pci-e bandwhich really make any difference.

sounds like crossfire left the old realm, of copy all to both cards, process 1/2 on each. to how that hybrid ati + nvidia card tech was gonna work.

maybe this will also result in closer to 100% scaling now.

even ati said in 4870's time that the crossfire link had become pretty useless and only became a bus used to say "hello" and initiate crossfire.