Trident CYBER 8820 and acceleration

[Marc Singer <elf@buici.com>]

I upgraded to 4.2.1-0pre1v1 on a Toshiba Laptop in an attempt to
improve driver throughput.  Oddly, the trident driver as packaged in
this version is slower than the frame buffer driver in 4.1.  The most
obvious change is that dragging windows around the screen shows
noticeable trails.  Now, I wouldn't have thought much about this
except that when I installed Alan's binary driver I found a
significant performance increase.  Is this performance difference
explained by debug code in the driver?