🚀 go-pugleaf

I'm curious.  What are the speed differences between ModeY and 13h?  In
my tests, 13h has always come out on top many times over (even copying
4 bytes at a time in VGA RAM).  Why is this?  As offered to me by a friend,
the VGA card is on an 8 mhz bus...so graphics transfers are only at 8mhz.
If this is the case, the ratio between ModeY and 13h should be fairly
close.  This is not happening, though.  Can anyone offer a valid explanation
of why this is?  ModeY offers some very valuable techniques (panning,
split screens, etc), but I can't afford the move to it if my programs
slow down.  I've been working with the tweaked modes for about 8 months
now, and in using every trick in the book, I can't get this to work at
the same speed.

Please, if possible, keep any discussion about this to rec.games.programmer.
There are some other people asking the same questions.

Thanks in advance,
Josh