[comp.sys.ibm.pc.misc] How much fast is a DX than a SX "really"?

frank@odetics.com (Frank Merrow) (12/14/90)

This is a question for one of you system guys out there.  If I take a 386SX
running at 20MZ and compare it to a 386DX running at 20MZ, how much faster
is the DX likely to be in "real life".  On the face of it the DX could be
twice as fast in some applications, but for the most part I suspect it would
be MUCH less.  Consider:

1. Most Video boards are 16 bits anyway so there should little if any gain
there.

2. There are probably some high end 32 bit disc controllers, but my guess
is that most are not (and are probably DMAed anyway).

3. A true 386 program might actually do very well with the wider bus, but
most programs are 8086 based and thus use shorter instructions and addresses
so might not run much faster at all.  Thus Windows 3.1 might take a performance
hit, but dozens of other more standard programs might show little change
at all between the two processors.

I am a software guy and only have enough hardware experience to make me
extreemly dangerous.  Does anyone out there have hard numbers in this area?
How much faster is that DX "really"?

Frank
frank@odetics.com or uunet!odetics!frank