al@well.sf.ca.us (Alfred Fontes) (06/24/91)
I followed the directions in Chaper 12 of my spiffy, new DOS 5.0 manual about loading everything into high memory. Unfortunately, EMM386.EXE seems to slow Hyperdisk down, on the order of 50%. Has anybody else had this problem? What can I do about it? Al Fontes, Jr. -- al@well.sf.ca.us -- -- uunet!apple!well!al --
maurice@sol6.cs.monash.edu.au (Maurice David Castro) (06/24/91)
From article <25639@well.sf.ca.us>, by al@well.sf.ca.us (Alfred Fontes): > I followed the directions in Chaper 12 of my spiffy, new DOS 5.0 manual > about loading everything into high memory. Unfortunately, EMM386.EXE > seems to slow Hyperdisk down, on the order of 50%. > > Has anybody else had this problem? What can I do about it? > > Al Fontes, Jr. > -- al@well.sf.ca.us -- > -- uunet!apple!well!al -- I make no use of hyperdisk, however, my 386sx has a bios which supports so called "extended features", the memory manager provided with the machine has served me well and is LIM4.00 standard so I took the path of least risk and used the built in EMM. I think that you will probably be able to use the original memory manager you were using before DOS5 came along provided it is compliant with either LIM3.2 or LIM 4.0 compliant (quoting the DOS 5.00 manual). Apart from being the standard for LIM there seems to be no advantage in using EMM386. The memory savings gained by DOS 5 are dependent on high memory not on Extended/Expanded (I can never remember which one is which) so are not dependent on EMM386 WARNING: If you suspect that your original memory manager is going to cause problems, then do NOT attempt what I have outlined! Merely because it appears to work safely in one circumstance does not guarantee safe operation for all. Maurice Castro - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - maurice@bruce.cs.monash.edu.au (Disclaimer: All care taken, but no liability accepted)
drudetb@infonode.ingr.com (Ted B. Drude) (06/26/91)
In article <4481@bruce.cs.monash.OZ.AU> maurice@sol6.cs.monash.edu.au (Maurice David Castro) writes: >From article <25639@well.sf.ca.us>, by al@well.sf.ca.us (Alfred Fontes): [...] ]>> Unfortunately, EMM386.EXE seems to slow Hyperdisk down, on the >> order of 50%. Has anybody else had this problem? What can I do about it? [...] >> Apart from being the standard for LIM there seems to be no advantage >> in using EMM386. >Maurice Castro [...] My own testing of EMM386.SYS vs. Quarterdeck's QEMM386.SYS shows that the Microsoft driver is considerably slower under DOS 3.x and 4.x. The generic OEM 386 LIM drivers provided with most new systems are similarly faster. I haven't studied the source code, but it seems that Microsoft almost deliberately slowed down their EMM386 driver, or they simply didn't know how to program the '386's memory paging architecture very well. -Ted Drude (drudetb@ingr)