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From: bb@wjh12.harvard.edu (Brent Byer)
Newsgroups: comp.arch,comp.sys.intel
Subject: Re: i860 overview (long)
Message-ID: <344@wjh12.harvard.edu>
Date: 11 Mar 89 19:40:26 GMT
References: <807@microsoft.UUCP> <92634@sun.uucp> <13322@steinmetz.ge.com> <1133@auspex.UUCP> <12000@haddock.ima.isc.com>
Reply-To: bb@wjh12.UUCP (Brent Byer)
Organization: Textware Intl., Cambridge MA
Lines: 78

In article <12000@haddock.ima.isc.com> suitti@haddock.ima.isc.com (Stephen Uitti) writes:
>In article <1133@auspex.UUCP> guy@auspex.UUCP (Guy Harris) writes:
>
>>> [Provoked by this bogus claim by Bill Davidsen:]
>>>One of the people here checked his Sun-30 (68020) against his Sun-4
>>>(SPARC). The three ran troff about 5x faster.
>
>> [ from Guy ]
>>I tried comparing "troff"s on a Sun-3/50 with 4MB memory, and a
>>Sun-4/260 with 32MB memory, both running 4.0.  Here are the times:
>>
>>Sun-4/260:
>>	auspex% time troff -t -man /usr/man/man1/csh.1 >/dev/null
>>	24.4u 1.2s 0:34 75% 0+456k 26+38io 31pf+0w
>>	auspex% time troff -t -man /usr/man/man1/csh.1 > /dev/null
>>	24.4u 1.5s 0:36 71% 0+464k 1+35io 0pf+0w
>>
>>Sun-3/50:
>>	bootme% time troff -t -man /usr/man/man1/csh.1 >/dev/null
>>	118.9u 1.2s 2:08 93% 0+208k 14+33io 24pf+0w
>>	bootme% time troff -t -man /usr/man/man1/csh.1 > /dev/null
>>	120.2u 2.8s 2:31 81% 0+192k 5+32io 11pf+0w
>>
>>The 4/260 did 5x *better* than the 3/50, not 5x *worse*, on that example!
>
> [ Stephen Uitti : ]
>The VAX 780 here running 4.3 BSD had this to say:
>
>	haddock% time troff -man /usr/man/man1/csh.1 >/dev/null
>	90.8u 6.4s 36% 95+201k 59+15io 24pf+0w
>
>I thought Sun 3's were lots faster than 780s.  Maybe more
>expensive Sun 3s are faster... 

All Sun-3's will run troff faster than any 780, providing that
one starts with the *same* troff sources and the *same* test data.

In the comparison (sic) alluded to above, Guy is using the
"old" troff (otroff, from the C/A/T era), but Stephen used a
DWB-based troff.  The "-t" option is the giveaway.

For comparison, if we rate otroff as 1.0, a DWBv1 troff will get
about 1.15, and DWBv2 troff gets 1.7 .  [ We have a souped-up
DWBv2-based troff that gets 2.2 ; anybody wanna race? ]

>  ....   Of course, my /usr/man/man1/csh.1 could be differant, ... 

And, Stephen is also using different, and less demanding, input data.
The csh.1 with SunOS4.0 is typographically more complex than either
of those in SunOS3.x or 4.3BSD.  All other things equal, it will
require about 80-90% more CPU time.

>Also, I think 'troff' is one of those applications that has odd
>behaviour compared to just about anything else one would run.

This is a *false* supposition.

>It should be pointed out (if it hasn't been already) that troff
>doesn't do nearly the byte accesses that one would think it should do.

True.  Other than fetches from its input buffer and stores into its
output buffer, there are few.  Remember, a troff "character" has a
much richer personality than just its code value.  In otroff,
it was a 16-bit datum, in DWB a 32-bit.

>Still, troff is a great benchmark for sites that do alot of troff.

Here, it is better to generalize:
	XXX is a great benchmark for sites that do alot of XXX.
(But, you all know that.)

------
	Brent Byer  (bb@wjh12.harvard.edu  or  att!ihesa!textware!brent)

12-year old nephew:	Uncle Bill, that steamboat race was the biggest
			  gamble in the world.
W. C. Fields:		Son, that was nothing.  I remember when Lady Godiva
			  put everything she had on a horse.