> at max heat, the speed is reduced approx. 20%, effectively 
> bringing that bridge do a 100 MHz machine.. 50 degrees Celsius 
> appears to be the top of the smooth running area performance of 
> that chip in particular, ass well as many of the others on board 
> are rated for running good between 15 and 45 degrees Celsius...
> I do not know how hot that is, it is off the sp

You don't need to worry about the speed vs temp parameters, the overall
design is supposed to work worst-case without having to derate the system,
if that's what you meant. (Plus, that worst case is over all possible
production variations, plus test equipment measurement error, plus the max
supply deviation.)

The part you are replacing was only rated 0-70 anyway, and all the post-74F
logic familys (e.g., ABT) use a lot less power and hence run cooler.

	ross