From: cline@ee.ualberta.ca (Robert Cline)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Supra XP 500 vs GVP Series II
Keywords: hard drive, ram
Date: 15 Apr 92 19:39:44 GMT
Organization: University Of Alberta, Edmonton Canada

clare@nynexst.com (Clare Chu Ayala) writes:



>  I know this has been asked before, but I'm torn between getting
>  a Supra XP 500 vs GVP Series II harddrive expansion for my A500.
I was too, when I was looking for mine. I bought the Supra, and I'll
tell you what I've found...

>  I've heard of people having problems with the GVP where the drive
>  stops spinning, and the fan goes up and down.  
Hmm, never heard of that one, though.

>  I'm also interested in the differences between RAM expansion.
>  The GVP is relatively straightforward.  There are four SIMM
>  slots.  You can either plug in 1x8 Simms or 2 4x8 Simms (to get 8 Mg).
>  Does anyone know if you can plug in 1 4x8 Simm to get 4 Megs
>  instead of 4 1x8 Meg Simms?  Right now I only want max of 4 megs,
>  but you never know about later on.
The Amiga uses 16-bit wide memory only... a 4Megx8bit simm only
provides half of that- that's why they're always paired up.

>  The Supra configuration has me more confused.  I called them and
>  the guy said that you had to buy the one with 2 Megs installed to
>  get more than 2 megs.  If you buy the one with 1/2 meg installed
>  you can only get a maximum of 2 megs!  That didn't make sense to
>  me, as I thought, why can't I take out the 1/2 meg (which is 2
>  256x4 Dram) and plug in the 1x4 Zip?  It seems like there are
>  only 2 slots available (is that true?)  And also is it true that
>  if you need to expand further than 2 Megs you need to buy another
>  ram expander board?  
Basically, what they mean is that using 256x4 Dram, you can put in a
maximum of 2 megs (8 sockets total), but yes, if you take those out you
can use 1x4 Zips, it's just then you got 1/2 Meg sitting around. Also,
to use Zips the 'expander board' is basically just to adapt Zip sockets
for the Dip sockets inside the XP's case, since 1x4 Dips are either
nonexistant or hard to find (I forget which).

>  Finally, I'm interested in how important is the low power consumption
>  of the Supra.  The guy on the phone claimed that it didn't need an
>  extra power supply.  However I'm planning on getting one anyway.
>  I'm concerned about GVP using too much power.  I don't want to
>  drain too much power from my wall socket.  Right now, everything
>  (Amiga, monitor, HP DeskJet 500, Supra Modem) is hooked to a power strip.
>  Isn't something bad likely to happen if you have too many things
>  drawing power from one socket?
You don't need to worry about how much they drain off your house current-
no computer should drain that much. You do need to worry about how much
you drain off the computer's power supply. The Supra claims that even with
a drive, it & the drive don't take too much of the stock Amiga 500 power
supply, but many people don't believe this, and claim your supply will
wear out faster. Since I already wore out one supply just using 2 floppies,
I got an IBM power supply cheap, and it had the connectors for hard drives
already sticking out of it, so that's powering my (now two) drive(s). For
more than one drive, the extra supply would be a necessity. If you have
for some reason gotten a bigfoot or something, don't worry about another
supply. The GVP uses it's own supply for the drive (& memory I think)
so you woudln't worry about it at all (unless the problems you mentioned
were due to it being a lousy power supply...)


>  Finally, what other Amiga hardware (boards) use the 1x8 Simms and/or
>  the 1x4 zips?  This is to maximize my reuse of chips in case I
>  get a 3000 or something.  Not likely at the moment, but just to keep
>  in mind.
It seems to me a lot of GVP equipment uses the same simms, except for
boards that use 32-bit wide simms. You'd have to check on the ram the
3000 uses (I don't know- I only wish I could afford one :)

>  Thanks for any information on the two, or any comments on other
>  configurations.
Two additional comments: First, the major deal between these two drives is
price & performance. The Supra is way cheaper to start out with, and you
can buy the power supply if you need it later- that's why I bought it. The
GVP is supposed to be way faster, comes with it's own supply, and uses
the standard simms, so it's worth and costs more.
Second, since the GVP is DMA-driven, it delivers better performance on a
stock 500, but can lead to problems if you want to accellerate your
machine- typically 500 accellerators don't allow DMA into their ram, so
the drive performance goes way down as the system compensates with buffering
and I've heard of problems using AdSpeed with a DMA-based controller, as
it's cache needs to be flushed before any DMA.

All in all, I'd say if you're going to use the unacclerated 500, and can
afford it, get the GVP. I liked the base price of the Supra, but would've
bought the GVP if I could have afforded it right off the bat.
Incidentally, on an accellerated 500 my Supra worked about 2-3% faster
than normal.

>  Clare

Rob Cline