From: hades@coos.dartmouth.edu (Hades)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Accelator for ci?
Keywords: IIci, accelator
Date: 7 Oct 92 14:50:12 GMT
Reply-To: hades@Dartmouth.Edu
Organization: Dartmouth College, Hanover, NH
Disclaimer: Personally, I really don't care who you think I speak for.
Moderator: Rec.Arts.Comics.Info

peterbak@microsoft.com (Peter Bako) writes:


>With everyone drooling over the speed of the Quadras, I'm starting
>to feel a bit left out.  So I'd like to get an accelator for my CI.

    Sounds good, but since your ci already runs at 25mHz, you will need
to buy at least a 33mHz accelerator for it to really do anything, and
they can get pretty expensive.

>The only catch is that it seems like everytime I read about the 
>pros and cons of any accelator they seem to contradict each other.
>For example the Radius Rocket seems to be the most optimal, but
>some of the info that I have received suggests that since it goes into
>a NuBus slot instead of the PDS it might have some problems.  Also
>it requires its own bit of memory which is extra cash...

    If you install an accelerator card into a NuBus slot, you sometime
run into a bottleneck because of the transfer rate of NuBus. This is why
a Rocket isn't always the greatest accelerator to buy. If you happen to
have a Mac with a PDS slot however, and you can get an accelerator for
it, then you are better off because the PDS slot talks directly to the
CPU, without tne problems of the NuBus interface and bottleneck.

>On the other hand I have little information about the best kind of
>accelator for the PDS.

    There is no PDS slot in a IIci. There is, however, a cache slot,
which works differently than either a PDS or a NuBus slot.

>Can anyone send me recommendations, problems, etc. on accelators for the
>CI?  Also info on program compatability would be great.

    Probably the best accelerators on the market (that aren't '040
accelerators) are the DayStar PowerCache cards. I bought the 50MHz
version for my boss's SE/30, and you should see this machine fly. No
compatibility problems whatsoever, running tuned 7.0.1.

>Also someone posted a question here regarding problems with the internal
>video driver of a CI if you install 4m SIMMS into bank A.  Since I am also
>planning on adding more memory to my system, I'd like to hear anything
>about this.  Is this a true problem or what?

    The on board video of the IIci uses system RAM to store the video
information. The IIsi does the same thing. Both machines use available
RAM from bank A for this task. Since on the IIsi, bank A is fixed at 1MB
there is less likely to be any problems with using all of that for the
video and putting 4MB in bank B to be used for the system. But in the
IIci you must put the highest memory in bank A, and if that is 4 4MB
simms then there can be problems with your computer wrestling with the
on board video for space within that 16MB. The only effect it might have
is a slight slow down in video performance.

--
-Hades (Brian V. Hughes) 
   "You know Television has gone to hell when, with every commercial,
	 you find yourself hoping to see the Energizer Bunny."
Newsgroups: comp.sys.mac.hardware