Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!brutus.cs.uiuc.edu!wuarchive!wugate!uunet!mcvax!sunic!kth!draken!bmc1!kuling!irf
From: irf@kuling.UUCP (Bo Thide')
Newsgroups: comp.sys.hp
Subject: Re: Floating point accelerator 98248a
Message-ID: <1137@kuling.UUCP>
Date: 16 Aug 89 21:57:31 GMT
References: <112@engr.wisc.edu> <5570266@hpfcdc.HP.COM>
Reply-To: irf@kuling.UUCP (Bo Thide')
Organization: Dept. of Computer Systems, Uppsala University, Sweden
Lines: 30

In article <5570266@hpfcdc.HP.COM> rjn@hpfcdc.HP.COM (Bob Niland) writes:
>re: wittmann@engr.wisc.edu (art wittmann) writes....
>
>> I just got a 98248a FPA for my 9000/360.
>> ...
>> ...saw about a 10% performance increase.  
>
>The recommended FPA for the 360/370 is the 98248B.  The 98248A was
>optimized for the 330 and 350.  Offhand, I'm not sure if the 10% result
>is typical for your configuration.
>

I had a 9828A for my 350 and saw a 100-250% performance increase in a
very floating-point oriented test.  When I upgraded to the 370 I also
changed to the 98248B (Dragon II) and saw a somewhat lower performance
increase.  This is probably due to the fact that the 33MHz 68882 in the
370 is much faster than the 20 MHz 68881 that I had in the 350 so the
difference between the coprocessor and the FPA is smaller in the 370.
Of course, the 370 + Dragon II is a faster floating point machine than
the old 350 + Dragon I but not as much as I had hoped.  I understand the
300 series FPAs are manufactured by Intel (?).  Why didn't HP choose to
replace Dragon I with a similar PFA as in the 9000/835 which is *much* faster?


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