Author: Robert Hyatt
Date: 10:50:13 03/05/98
Go up one level in this thread
On March 05, 1998 at 13:46:21, Ernst A. Heinz wrote: >On March 05, 1998 at 12:29:24, Albert Silver wrote: > >>On March 04, 1998 at 08:39:33, Robert Hyatt wrote: >> >>>On March 04, 1998 at 01:15:54, Jouni Uski wrote: >>> >>>> >>>>>This has to be operator error, because there is *nothing* in win95 that >>>>>will cause this behavior, other than setting hash tables a little too >>>>>big >>>>>and causing swapping... >>>>> >>>> >>>>It is not any operator error. Specially in endgames Genius in dos (/X) >>>>mode is often 2X faster, than windows version even with about same >>>>hash sixe. >>> >>>I don't want to get into a heated argument here, but my background is >>>operating system development, and I've been in that environment for >>>almost >>>30 years, and I can't think of a single reason why a program would run >>>2x >>>slower under win95, if you discount the paging problem. And if you >>>discount >>>the problem of having multiple applications running and sharing cpu >>>resources. >>> >>>Other than those two things, there is *nothing* I can think of that >>>would >>>cost you 2x. You ought to run the windows resource monitor to see what >>>is >>>going on, because I have never seen this outside of the two exceptions >>>mentioned above... >> >>Well, I can't comment on Genius 5 as I don't have it, but I have noticed >>a similiar (80% difference on the average) performance hit when running >>Mchess 7.01 in DOS as opposed to Win95. I can assure that it is not due >>to any TSRs or other software running in the background as if I call up >>the special Rebel9 windows shortcut it runs almost identically in speed >>as when run in DOS. I have no explanation for it but I can give you test >>suite results with the resource monitor's results as well for your >>examination. >> >> Albert > >A plausible explanation for this strange behavior might be that task >switches under Windows NT/95 badly thrash some CPU internals (caches, >pipelines, branch prediction units etc.) -- I remember having read >some tests which suggest exactly this. Some integer-bound applications >therefore seem to run much slower under Windows NT/95 than under DOS. > >=Ernst= This is certainly possible, but if you are *only* running a chess program, what possible task switches could be done, other than to occasionally flip into the win95 interrupt handler for clock interrupts?
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