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- Newsgroups: comp.sys.apple2
- Path: sparky!uunet!usc!sol.ctr.columbia.edu!destroyer!ncar!csn!teal!bazyar
- From: bazyar@teal.csn.org (Jawaid Bazyar)
- Subject: Re: Accelerator Performance
- Message-ID: <bazyar.716237417@teal>
- Sender: news@csn.org (news)
- Nntp-Posting-Host: teal.csn.org
- Organization: Colorado SuperNet, Inc.
- References: <9209110433.AA12247@pd-dom.wl.com>
- Date: Fri, 11 Sep 1992 18:50:17 GMT
- Lines: 44
-
- schultp@wl.com (Paul Schultz) writes:
-
- >I am going to be getting an accelerator for my IIgs
- >in the near future and have a few questions:
-
- >1. A significant performance increase is seen with a
- > 7 or 8 MHz ZIPGS but how noticeable is the performance
- > increase between some of the upper speeds (i.e., from
- > 7 MHz to say 9 or 10 MHz)?? Since cost is a big issue
- > for me I don't want to waste money on a 9/10 MHz card
- > when a 7/8 would really do the job for me.
-
- Yes, there is a noticeable difference, especially in graphics with
- the Zip from 7MHz/16K to 9MHz/64K. It's about a 25% increase in general
- system performance. (as you might guess from 7/9).
-
- >2. What are some of the system bottlenecks that would cause
- > the effective increase in performance to "plateau" at the
- > higher speeds.
-
- Graphics, but a large cache fixes that. That, and disk I/O is
- pretty much it.
-
- >7 MHz, 8Kb ZIPGS
- >Apple High Speed DMA SCSI card.
-
- >Do these two cards match up fairly well?
-
- >4. Oh, one final thing! With the proposed set-up what would be
- > the most cost effective Cache size for the ZIPGS?
-
- You want the biggest cache you can afford. 32K wouldn't be a bad idea.
- 64K will make that 7MHz work for you as much as possible.
-
- The DMA SCSI is pretty nice; it's probably on average as fast as a RAMfast
- on reads, but definitely not on writes; the RAMfast accepts the data for a
- write and then returns control to the computer immediately; the actual
- write to disk occurs in the background.
-
- --
- Jawaid Bazyar | Ask me about the GNO Multitasking Environment
- Procyon, Inc. | for the Apple IIgs!
- bazyar@cs.uiuc.edu | P.O Box 620334
- --Apple II Forever!-- | Littleton, CO 80162-0334 (303) 933-4649
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