brianm@sco.COM (Brian Moffet) (11/14/89)
Using intensive math (floating point) what kind of performance can I
expect to get by using a 68881 as a peripheral to the 68000? I am
looking at floating point ray-tracing programs as my major use of this
chip, so I want to be sure it would be worth my while.
I have an Amiga 1000 with Starboard II memory board which has the ability
to have a daughterboard with a 68881.
thanks
brian moffet
--
Brian Moffet {uunet,decvax!microsoft,ucscc}!sco!brianm
-or- ...sco!alar!brian
"I was everything you wanted me to be. You were afraid, I was frightening."
My fish and company have policies. I have opinions.mlandis@nmsu.edu (Marvin Landis) (11/15/89)
In article [3759@scolex.sco.COM] Brian Moffett asks: > Using intensive math (floating point) what kind of performance can I > expect to get by using a 68881 as a peripheral to the 68000? I am > looking at floating point ray-tracing programs as my major use of this > chip, so I want to be sure it would be worth my while. > I have an Amiga 1000 with Starboard II memory board which has the ability > to have a daughterboard with a 68881. I had a Starboard II and the daughterboard for the 68881 on my Amiga 1000, and thought I would be able to speed up my ray tracing with it. However, none of the major ray tracers available for the Amiga support the 68881 on the Starboard II. Sculpt, Turbo Silver, and Opticks are all written for 68020(030)/68881(882) combinations and will not work with just the 68881 on the Starboard daughterboard. I talked with Byte by Byte about this and they claimed they had bought Eric Graham a Starboard and 68881 combination, he changed Sculpt to use it, and it was slower than the normal 68000 version of the software. So beware, if you are writing your own ray tracing software, you MIGHT be able to achieve some speed up using this combination, however if you are relying on commercial packages, none will take advantage of the 68881 without a 68020 or 68030 board also installed in the machine. Marvin Landis mcsmal@nmsuvm1.bitnet mlandis@nmsu.edu