[comp.sys.ibm.pc.hardware] S.I. and "expanded or extended" on 386SX

ong@d.cs.okstate.edu (ONG ENG TENG) (01/04/91)

Thank you all for the answers and comments on the S.I. index and
"expanded or extended" questions.  Since I got quite a few emails,
I shall post my followups.

As for "expanded or extended", what I mean to ask was whether
should I configure it as expanded (as it is an option in NEAT chipset) or
use the QEMM.SYS on the regular extended (after I have configured it
that way).  In both cases, I want to use the memory as only
expanded memory (and expanded memory only, no need for extended).  The
question is whether the QEMM.SYS on extended is faster or the
NEAT chipset configured "hardware" expanded memory is faster?

The S.I. index on my 386SX (my S.I. is version 3.1, maybe there is a
problem there) is 15.3 at 16MHz with 0 wait state.  What happen when
I switch it to 1 wait state?  It drops to 12.6!  To be fair, the
386 memory management is much much more complicated and advanced
(thereby slowly it down?)
and I would trade some speed especially it is so small for the 
advance memory management any day!  

Also, does anyone has the Landmark speed index program (and the usual
where-you-get-it-and-how-much)? Is it more valid than S.I.?  Does it
take math coprocessor in account?  This is because I wanna to know
how much faster is a 486 compare to 386 when floating point is NOT
in use.  Landmark number published seems to indicated 486 double the
computing power of 386.  See, since Wing Commander, I can see
great simulator games going the direction of ray-traced graphics
used as bit-mapped on the run, thereby cutting the need for a
math coprocessor (which is more necessary in the case of
randering as opposed to bitmapping).  Should one consider a cached 386
or 486 keeping in mind the price/performance ratio?

E. Teng Ong (ong@d.cs.okstate.edu)

dlow@pollux.HP.COM (Danny Low) (01/05/91)

>(ONG ENG TENG) 
>As for "expanded or extended", what I mean to ask was whether
>should I configure it as expanded (as it is an option in NEAT chipset) or
>use the QEMM.SYS on the regular extended (after I have configured it
>that way).  In both cases, I want to use the memory as only
>expanded memory (and expanded memory only, no need for extended).  The
>question is whether the QEMM.SYS on extended is faster or the
>NEAT chipset configured "hardware" expanded memory is faster?

The EMS standard requires a EMS driver as well as EMS memory. Does your
system come with an EMS driver? If not then go with QEMM.SYS.
That not only "convert" XMS to EMS but also functions as the EMS
driver.

			   Danny Low
    "Question Authority and the Authorities will question You"
	   Valley of Hearts Delight, Silicon Valley
	     HP CPCD   dlow@pollux.svale.hp.com