At 10:16 PM 7/17/1998 Joel Bluming wrote:

> Is there a way to decifer
>which jumpers control the speed and which control the multiplier?

As John Chin pointed out, you only need to change the bus speed to
40 mhz from 33 mhz to switch from the 100dx4 to the 120dx4.
Although AMD no longer hosts all the pages about the 486 that they
did at one time, I have hard copy of most of it and they don't mention
any serious consequences in their FAQ about getting the jumpers wrong,
just that the PC won't boot or run consistantly.  You could try experimenting
by comparing the jumpers to what the settings are for the AMD 486 DX2/80,
which is also a 40 mhz cpu and should be listed for the OPTI.

As for the floating point performance, the same patent restrictions that keep
the pentium's performance out in front of the competition did not exist for the
486, so basically the AMD is a clone and will perform about equal to a comparable
Intel 486 for floating point math.

Tom Turak