Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!agate!usenet.ins.cwru.edu!ncoast!davewt From: davewt@NCoast.ORG (David Wright) Newsgroups: comp.sys.amiga.advocacy Subject: Re: Blitter vs. 040 (was: Computer Architecture question Message-ID: <1991May15.125954.1993@NCoast.ORG> Date: 15 May 91 12:59:54 GMT References: Organization: North Coast Public Access Un*x (ncoast) Lines: 52 In article melling@cs.psu.edu (Michael D Mellinger) writes: >Hmmm. 1+1 != 3. You could have the 68040 do the graphical work then >do the calculations then do the graphical work all in the same time >that it took the blitter to do the the graphical work and the 68030 to >do the calculations. In other words, the 68040 gets more work done in >the same period of time. Can you REALLY be this dumb? The point people have been trying to make is that if a 68030+blitter is faster than just a 68030, then a 68040+blitter will be faster than just a 68040. Of course a 68040 will be able to update screens faster than the blitter in many cases, but in doing so it will be stealing time that could have been handling OTHER programs, just to update the display. Gee, this sounds just like the nExt. No wonder you can't understand it. Where will your argument stand with a 3000 with an 040 in it? You are still trying to compare a 68030 machine to a 68040 machine, like you were 3 months ago. Don't you notice how SLOW the nExt updates it's windows and displays (not what is happening within them, but move a window around and see how long it takes to redraw the display (especially with 5 or 6 windows open)) when compared even to an Amiga 500, a 16-bit machine running at 7Mhz. > >So the CPU has to stop and update the screen. What's the big deal? >You have 2*N mips in your machine and N of those mips are only capable >of bit manipulation, while the other N mips can be used for your ray >tracer. Drop an 040 in the A3000 and you now have 3*N mips for >calculations and you still only have have N mips for bit >manipulations. The point is, what if you have SOMETHING ELSE running as WELL AS the ray tracer. Why should EVERY program, EVERYWHERE have to slow down just to make the screen update MAYBE 1/10th of a seccond faster? >Assuming you have 1 meg. Amiga. When you exand the Amiga to 1 meg. is >512K chip RAM and 512 FAST ram? Don't you mean "assuming you have at least 1 meg Amiga"? In fact, under some A500's the first meg is 512k of CHIP, and 512k of "slow fast" RAM. On other Amiga's it is 512k CHIP and 512k "true" FAST RAM. Anything you add beyond that is always "fast" RAM. So my 3000 has 2 megs of CHIP RAM, and 16 megs of FAST RAM. >Are people still writing directly to the hardware on the Amiga? What is this? The old "oops I'm getting my butt kicked here, lets quick change the subject to something else" trick? We were talking about whether a 68030+blitter is faster than just a 68030, and therefore whether a 68040+blitter is faster than just a 68040. You just don't seem to understand that: 1) Using the blitter is NOT mandatory 2) There are ways to even disable it at the system call level 3) Having two CPUs is ALWAYS faster than just 1, as long as you pick the jobs that each does correctly Dave