Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!snorkelwacker!spdcc!merk!alliant!linus!brando From: brando@mitre.org (Thom Brando) Newsgroups: comp.sys.mac.hardware Subject: Re: Mac II Accelerators Message-ID: Date: 7 Nov 89 15:35:21 GMT References: <15435@bloom-beacon.MIT.EDU> Sender: brando@linus.UUCP Distribution: usa Organization: Mitre Corporation, Bedford, MA. Lines: 30 In-reply-to: daemon@bloom-beacon.MIT.EDU's message of 27 Oct 89 02:26:46 GMT >> Has anyone out there had any experience with [the Daystar Digital >> Accelerator II]? Is it a good product? If not, can you suggest other >> accelerator which would be better? I just put a 40-MHz Accelerator II in my Mac II recently and have been very pleased (so far :-). I haven't found anything that runs on an SE/30 that doesn't run on the accelerator board. (This means I've been able to run MacWrite II, MacDraw II 1.1, MacTerminal 2.3, Microsoft Word 4.0, PageMaker 3.02, Illustrator 1.8.3, Freehand 2.0, Allegro CL 1.2.2, and Smalltalk-80 v2.5 (some more extensively than others, of course :-). I also use QuickMail 2.01, Master Juggler 1.50, and MacroMaker 1.0.1.) As far as speed in concerned... I expected the 40-MHz accelerator to outperform a 16-MHz SE/30 by a factor of 2.5. We ran an assortment of timing tests using Allegro CL, and got execution times that were faster by almost exactly a factor of 2. So where did the other .5 go to? Well... unfortunately, the installation manual I got with the accelerator didn't say anything about this extra little jiggy that came with the accelerator, so the jiggy never got installed. I spoke with Daystar later and found out that the jiggy is their own PMMU which is supposed to replace Apple's AMMU and thereby eliminate a wait state that's incurred for every memory access that goes through the MMU. I have yet to install the jiggy, but when I do, I'll run my timing tests again and see what happens. Also, I believe the 50-MHz board is now available, and I'm waiting for my free upgrade... yummmm! -- Thom Brando (617) 271-3947 The MITRE Corporation, m/s A129 brando@mitre.org Burlington Road, Bedford, MA 01730 ...!linus!brando