Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!ginosko!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: 68030 Accelerators, Info Wanted
Message-ID: <8182@cbmvax.UUCP>
Date: 13 Oct 89 16:16:51 GMT
References: <19968@unix.cis.pitt.edu>
Organization: Commodore Technology, West Chester, PA
Lines: 36

in article <19968@unix.cis.pitt.edu>, ejkst@unix.cis.pitt.edu (Eric J. Kennedy) says:

> In article <517@aucis.UUCP> easton@aucis.UUCP (Jeff Easton) writes:
>>  Wrong! The GVP comes with a IDE interface for a Hard disk that has
>>the controller on board.  

> My friend has this setup, with the Quantum 40 meg drive.  Since the
> system is running a 25MHz 68030, and the controller is 32 bit (right?)

The controller is 16 bit, non-DMA.  It's bascially a PC-AT expansion bus.

> Instead, the diskperf numbers are more like 450K per second.  

The other thing is, at least last time I checked, GVP device drivers were 
written in C.  If you use SetCPU, and can get a CARDROM entry for the GVP
ROMs (assuming they run directly from ROM and don't load that ROM code 
into RAM), you can boot performance a bit if you have 32 bit memory.

> This is respectible, (lots faster than my C.Ltd.!) but hardly up to the 
> 800K/sec that I've seen reported with, say, the HardFrame.  Is there 
> something that could speed this up, or barring that, an explanation for the
> relatively unimpressive speed?

The Hardframe, like the Commodore controllers, is DMA driven, and so you
can get over 1 megabyte/second, though the filesystem (FFS), with the
right hard drive (CDCs, not Quantums).  While the PC-AT bus is in theory
capable of 4 MB/s transfers, it's not clear that [A] the Quantum goes
anywhere near that speed, or [B] what the GVP interface can actually achieve;
it could be their interface to the AT drive is less than optimal.  And it
could always be software, too....

> Eric Kennedy
-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
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