20 Nov
2007
20 Nov
'07
8:47 a.m.
On 19 Nov 2007 at 23:03, Allison wrote:
Actually it's teh other way around the 386 was
more efficient than
286 for the same clock speed.
In 16-bit mode, I seem to recall that the 386SX was a travesty of a
CPU; a 16 MHz SX ran nowhere near as fast as a comparably-clocked
286. Early 386 boxes were nothing to crow about in 16-bit mode--and
a 32-bit software base pretty much didn't exist early on--and the
386SX was limited to 16MB of external memory, just like the 286.
Doubtless the 386SX board designs were low-budged also, which
probably figured into things. Some 286 vendors made a big thing of
the fact that a 286 could execute 16-bit real mode code substantially
faster than the 386SX. For example:
http://www.intersil.com/data/an/an121.pdf
On the other hand, the 386SX could execute 32-bit code. That is, if
you had any to run in 1989.
Cheers,
Chuck