Re: Wrong compilation artifacts on ES40s?

From: Bill Ross <>
Date: Sun 24 Jun 2001 12:58:33 -0700 (PDT)

        But somehow I am still suspicious because by default I guess
        Compaq gives 64bit architecture and it should be more accurate.
        Here it was only 100 steps. And for these 100 steps, IBM SP3
        (2-16 processors), Octanes (SGI), Alpha-Compaq work stations
        (stand alone), and Linux (1-12 processors) have given same
        numbers upto the last digit. I agree that I may be wrong. I
        shall do long time scale simulation soon and shall verify.
You may be right - I was reacting from earlier experience
porting Amber in single-precision. Which gives me a thought:
if the ES-40 is somehow running single precision, those subtle
deviations in all the numbers would be exactly what one would
expect. You should be seeing "-DDPREC" in the compilation
statements; if not, check src/sander/Makefile, where double
precision is enforced by "PREC=DPREC".

Bill Ross
Received on Sun Jun 24 2001 - 12:58:33 PDT
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