Path: utzoo!attcan!uunet!mcsun!cernvax!chx400!ethz!visinfo
From: visinfo@ethz.UUCP (VISINFO c/o Sascha Schnapka)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: GVP 3001 Caches
Keywords: 68030, Cache, chipcache, A3000
Message-ID: <6243@ethz.UUCP>
Date: 16 Oct 90 13:23:37 GMT
References: <3551@rwthinf.UUCP> <04071.AA04071@babylon.UUCP> <14811@cbmvax.commodore.com>
Reply-To: visinfo@bernina.UUCP
Distribution: comp.sys.amiga.hardware
Organization: ETH Zuerich, Switzerland
Lines: 23

In article <14811@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes:

 [some lines deleted]
>But I really don't see too much advantage to I-caching of Chip RAM.
>
I agree that it is definitely wrong to speak of a 'tremendous performance
increase' for Cache in Chip Memory.
Yet I was unsatisified with the fact that the A3000 is usually unable to 
provide it, even more now where the GVP has it.
There is in fact one case when you might like I-Cache in chipmemory:
for games like flight-simulators that place (like most games) their code
in chip-memory.
I have experimented with some and found that for example Starglider 2 by
Argonaut Software gives you a beautiful smooth moving 3D picture that
is indeed better than without cache.
Anyone who is interested can now download 'chipcache12.lzh' from
abcfd20.larc.nasa.gov to try having I-Cache in chipmemory on the A3000.
The solution I made is not the optimum, it globally disables Data Cache
to avoid Data Cache in chipmemory.
I will try to implement the idea with seperate instruction/data
translation trees too and will publish some speed comparison results.

F.Burgel     (BIX: hardwiz)