840/820 chipset

[dahlin@wa.freei.net]

I have recently run into some problems with graphics processors and the 840 chipset.
 On graphics chips from different vendors I have seen lockups occur during boot
or during entry into Windows.  These were tracked down and I found that in both
cases if a delay was added in the code where it is accessing registers in the
graphics processors the lockups would not occur.  (I found this when the debugged
version of the driver didn't lock).  It acts as though the writes are happening
too fast and I need to slow them down.  In fact, if I test it on a system with
faster memory (Rambus PC800) new lockups reveal themselves and that didn't occur
with SDRAM.
This doesn't make sense because one of the boards is on PCI 33 (the other is
1x AGP) and I can't imagine that the Pentium couldn't keep up with the PCI bus
until this new chipset came out.

Does anyone know of some new features in the 840/820 chipsets or significant
differences from the 440 that might reveal a cause for this behavior?

Thanks,
Jeff Dahlin