Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!bbn!oliveb!amiga!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: A2090A and Ronin 030
Message-ID: <7729@cbmvax.UUCP>
Date: 22 Aug 89 19:14:14 GMT
References: <34149@grapevine.uucp>
Distribution: usa
Organization: Commodore Technology, West Chester, PA
Lines: 47

in article <34149@grapevine.uucp>, stuart@grapevine.uucp (Stuart J. McIntyre) says:
> Keywords: 2090 2000 1.3 Ronin 68030

> With the ronin CPU/memory OFF the machine works great.  With maxtransfer
> set to 262144 on the FFS partitions we were getting 508K/sec.  But!!!
> in order to use the 68030 we had to add "Mask = 0xfffff" to the mountlist
> for each of the FFS partitions.  This dropped diskperf down to 80k/sec!!

Yup.  Look carefully at that mask value.  It has the effect of restricting
all DMA to Chip memory.  The result of this is that you're fast DMA disk
is now running about as slow as possible in such a system.  The only way
you can speed it up at all would be to DMA into Fast memory and then CPU copy
to Ronin RAM, but that's not going to be all that much faster.  

This is a two-way problem.  Obviously a DMA controller can't get to RAM that's
not in it's address space.  Only, the Ronin memory normally sits in autoconfig
space, though it doesn't autoconfig, and it's not DMA-able.  That's pure evil,
there aren't many other rule this Ronin RAM could have broken.  There's supposed
to be a way to move it up out of the autoconfig space -- I'd recommend that, as
that's where such memory belongs, if you have it -- out of the 24 bit address
space.  Then you can benefit as much as possible from expansion bus Fast memory,
and set your mask to 0xfffffe to keep the DMA within the 24 bit space.

> required to avoid the guru, (so now we have a 20 MHZ Amiga with a 
> quantum running at 80k/sec and 4Mb 32 bit ram but we can't remap
> kickstart into the fast ram without crashing.)

I suspect you have a 14.3 Mhz Amiga, perhaps with a 20 or 25MHz math chip, 
unless this is a new version of the Ronin card.  I hope not -- I'd like to
think they wouldn't introduce the same flaws twice.  They were the first 3rd
party 68020 design to at least get the basic bus interface stuff 100%, at
least as much as I've tested the thing (played with one for 2 weeks); why stop
at halfway right?

> Will a trump card (or Kronos card) solve the DMA/fast RAM problems?

Any non-DMA card will work faster in such a setup; C Ltd., IVS, or GVP are ones
I know of.  They still won't be as fast as DMA could be with an A2620 or A2630,
but they'll work FAR better than your current setup.

> -Stuart


-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
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            We have no choice.  We are, after all, professionals.