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From: karludo@insider.zer.sub.org
Newsgroups: comp.sys.amiga.hardware
Subject: GVP Impact II - Professional030 probs
Message-ID: <9106211453.21.145342@KARLUDO>
Date: 22 Jun 91 16:39:19 GMT
Sender: root@buchonia.rhoen.in-berlin.de (Big Brother)
Distribution: comp
Organization: fulmin Ebersburg/Rhoen
Lines: 34


  
Hi all.

My system consists of: Amiga 500, GVP Impact Series II A500-HD+ (LPS105),
Professional 030 Board w/ 1Meg 32 bit RAM (don't know if this one is
also common outside Europe).

The following problem arose: If the system runs without the 1Meg
32 bit RAM configured, DiskSpeed (and other speed tests, too)
show a data transmission rate of ~660kB/s.
But with the RAM turned on ("addmem 900000 a00000") the data rate
immediately drops to ~64kB/s! (No, I did not miss out a "0")
It even doesn't matter to push the 32 bit memory chunk to the end
of the memory list with pri=-20 (via XOper).

Without doubt this is because of the DMA-design of the hard disk, while
the RAM-expansion being unable to perform DMA-accesses.
But this does not justify a speed decrease by a factor of 10 at all!
Even if the data had to be shuffled around 5 times, this should not end
in *such* a lack of performance...

I *have* tried to ship around this by trying other values for Mask
(current setting: $3FFFFF) and the buffers, without success.

And no, this is not a problem of my A500, the same symptoms showed up
on my brother's A2000, too. (Same accelerator, same HD controller)

Maybe there are some guys from GVP around in this group willing to help.
NOTE: my old ST-502 HD ran at ~400kB/s with 32 bit RAM ON.

sigh...

  Kay-Uwe Drangmeister              ...cbmehq!cbmger!insider!karludo