Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!dimacs.rutgers.edu!rutgers!cbmvax!daveh From: daveh@cbmvax.commodore.com (Dave Haynie) Newsgroups: comp.sys.amiga.advocacy Subject: Re: RRe: Blitter vs. 040 Message-ID: <21614@cbmvax.commodore.com> Date: 15 May 91 19:31:38 GMT References: <9105132009.AAtau12911@tau.sm.luth.se> Reply-To: daveh@cbmvax.commodore.com (Dave Haynie) Organization: Commodore, West Chester, PA Lines: 41 In article melling@cs.psu.edu (Michael D Mellinger) writes: >In article <9105132009.AAtau12911@tau.sm.luth.se> d88-psm@sm.luth.se (Peter Sj|str|m) writes: > 7.6? Wow! I've almost bragged over my 5 MIPS. (ie. it's true!) You can probably get a real wide range of MIPS figures for the A3000 (or any other computer), simply by varying the "I" variable. > As I understand the A3000 with AMaxII even runs Mac-programs faster > than the Mac IIfx because of 1) the blitter (or whatever displaythingy there's > doing the job) and 2) only the 68030 and the cache is 40 MHz in the Mac. The > rest of the computer (memory etc.) runs on 20 MHz. I'm not familiar with > how much the NuBus does. NuBus on the Mac is only involved in graphics. You might see a faster display on an A3000 under AMaxII versus a Mac IIfx in some cases. I imagine any differences there is purely due to the bus bandwith; the A3000's bandwidth to video, when not overloaded (since AMaxII is only running black and white, it can't overload the A3000's display in any mode) is around 7 MB/s. I have heard the effective bandwith of earlier Mac IIs on NuBus is more like 5 MB/s, though I think the IIfx might be more efficient. In any case, I don't imagine any direct comparisons are all that common, since IIfx users tend to run 8-24 bit color displays. With 8-24 times the number of pixels to push around on the Mac, you can expect the Amiga display to be faster. IIfx peripherals are on a 20MHz bus, but that's not a big concern, since most peripheral things tend to generate wait states anyway. The IIfx cache supposedly keeps up with the 40MHz 68030. No DRAM keeps up with a 40MHz 68030, so the bus it's on probably makes little difference. The IIfx does apparently have a decent memory architecture, with special write latching DRAM modules. So I would expect CPU intensive stuff to go faster on a IIfx than an A3000. Never ran the race myself, though. Pricing being what it is, it's not a direct comparison, either. Unless price is no object, and you just want to race the top-of-the-line Amiga against the top-of-the-line Mac. -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "That's me in the corner, that's me in the spotlight" -R.E.M.