Path: utzoo!attcan!uunet!seismo!esosun!ucsdhub!jack!sdeggo!drew
From: drew@sdeggo.UUCP (Drew Dean)
Newsgroups: comp.arch
Subject: Re: missing Dhrystone 2.1 (1 of 3 &
Summary: Why does a 68020 have to thrash on I/O
	 at 100Mb ?
Message-ID: <228@sdeggo.UUCP>
Date: 21 Jul 88 04:29:38 GMT
References: <4232@cbmvax.UUCP> <76700035@p.cs.uiuc.edu> <9a0K/cbluk1010IHSPc@amdahl.uts.amdahl.com>
Organization: Lazy Programmer's Society of San Diego
Lines: 25

In article <9a0K/cbluk1010IHSPc@amdahl.uts.amdahl.com>, chuck@amdahl.uts.amdahl.com (Charles Simmons) writes:
> 
> (To follow up on the last comment of Tom's...  To really benchmark
> an Amdahl mainframe against other types of machines, we would prefer
> a benchmark that used over 100Mbytes of memory and which did lots
> of I/O.  It would be fun to publish numbers that show a 68020 based
> machine thrashing on the benchmark for many hours (days?) while the
> mainframe completes the job in a couple minutes.)
> 
> -- Chuck
Why would a 68020 thrash on a 100Mb benchmark, assuming the system has
enough RAM ?  I thought I've seen ads for 680x0 machines with 128Mb limits
on system RAM, am I just wishfully dreaming ?  Given that Cray disks are
18ms, (although they do transfer 10Mbytes/sec), one can buy 18ms, 320Mb
Priams (and also Maxtors, etc) ESDI disks, so access time isn't a major
factor.  (Aside:  Does anyone know how big Core's 10ms disks come ?  I know
they make a 40Mb drive, and drives as large as 250Mb, but do they make a
250Mb, 10ms drive ?)
While we're discussing 680x0 benchmarks, does anyone have any numbers for
the new Apollo machines, the 3500/4500 (25 & 33 Mhz 68030's/ = speed 68882
FPU) ?

Drew Dean
drew@sdeggo.UUCP
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