Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!sunic!ugle.unit.no!rubin.idt.unit.no!daglem From: daglem@idt.unit.no (Dag Lem) Newsgroups: comp.sys.amiga.advocacy Subject: Re: Blitter vs. 040 (was: Computer Architecture question Message-ID: <1991May16.203434.4709@ugle.unit.no> Date: 16 May 91 20:34:34 GMT References: <1991May15.125954.1993@NCoast.ORG> <1991May15.213917.11992@ugle.unit.no> <1991May16.043705.6698@NCoast.ORG> Sender: news@ugle.unit.no Organization: Div. of CS & Telematics, Norwegian Institute of Technology Lines: 88 In article <1991May16.043705.6698@NCoast.ORG>, davewt@NCoast.ORG (David Wright) writes: >OK, you're right, on the A500 the blitter is a real winner. But what is the >screen resolution you usually use on the 500? What's the number of colors? >Have you ever seen an A3000 running Workbench in interlaced hires, >16 colors? Give it a try! zzzzzzzzzz..... Ahhh, so you are comparing a 4-color system (the nExt) to a 16-color system, and are suprised that it takes longer to redraw the 16 color screen. I will pit my 25 Mhz 3000 against a 25 Mhz nExt in a REALISTIC window redrawing contest anyday, using a 4 color display, which just happens to be what I use all the time. Don't get me wrong. I'm not saying the NeXT is a wonderful machine. In fact, I haven't even seen one. I'm saying that the Amiga blitter is not very useful on a big display with colors (and I want to use a big display with colors). |> Besides, the SIZE of the display has nothing (or at least, SHOULD NOT |> have anything to do with how long it takes to redraw, when you aren't talking |> about windows covering the entire display. What I am talking about is things What? The resolution of the display determines the size of my windows. Of course I want to display as much information as possible (e.g. in Shell windows). |> >Personally, I really do like the blitter consept, but the blitter hasn't got |> >enough horsepower! |> Depends on what you want it to do. A 50 Hp engine might just barely |> push a Yugo, but wouldn't work for a Motor Coach. But I sure wouldn't mind |> having a 50hp generator on the motor coach to drive my electric system so |> the main engine wasn't loaded down or required. |> >Having worked a *lot* with the blitter on an A500, I realize I can get the |> >drawing done faster with the 68030. My guess (yes, just a guess - enlightenment |> So do it. You aren't EVER forced to use the Blitter. You use things |> like the Blitter and Copper when they are apropriate. You don't make |> excuses to use them, just because they are there. As far as I can tell, using the blitter on a large colorful display is never appropriate. The blitter WAS very useful in the A500. I quote from the Amiga Hardware Reference Manual: "When copying memeory, it is approximately twice as fast as the 68000, ..." "The blitter is particularly well suited to graphics operations." We don't use a 68000 anymore. We use a 68030. The blitter is still the same, and is doing its specialized tasks less efficiently than the general 68030. |> >Anyway, this can't be the intention of the blitter? To do next to nothing? |> >Wow it's got line drawing, polygon filling etc., but it's not doing its job |> >fast enough! |> Sure it is. Even a stock A500 refreshes it's screen faster than |> almost ANY other system you can buy, including Sun's, Intel-based Unix |> boxes, PC-Clones running Windows, and certainly the nExt. These systems use higher resolution displays. Even an old Sun 3/60 (1152*900, 256 colors) running twm under X is faster on refresh than an A3000 running Workbench in hires-interlace, 16 colors (assuming the 3/60 has enough memory to keep it from swapping). |> >You state that the NeXT is slow on display updating. Just wait till you try |> >the above mentioned Workbench setup. Try moving windows around. Try listing some |> >lengthy directories in a Shell window. |> I have. Try doing it on a nExt and then do the same on the 3000. |> "Listing things in a shell window" reflects more on the disk drive and CPU |> than the display. What were you using? An A500 running from floppies and a |> file lister that reads the whole directory and sorts it before listing? |> In terms of actually LOADING data from the disk, I still have not yet found |> any other computer that does it faster. MS-DOS "tricks" you into thinking it |> is faster, because it keeps all the critical info in one certain spot on |> the disk, which is basically primitive. The Amiga method is more flexible, |> but can be slower depending on what you are trying to do. But actually LOADING |> the data, once you have found it, the Amiga's floppies are still among the |> best. Ever try using the floppies under Unix on a PC-based machine? Yuch. |> > You don't get it! Listing lengthy directories in a shell window initiates scrolling of the text. Who is responsible for the scrolling? I'll give you a hint: It's not the 68030. zzzzzzzzzz.... This has NOTHING to do with floppies, sorting or anything else you mention. I seriously doubt you have ever tried running 16 color hires-interlaced Workbench. By the way, I'm using an A3000/25 too, not "An A500 running from floppies...". |> Dave -- __ / |> Shorter of breath / \ __ __ / ___ _ _ |> and one day closer to death. / |/ / / / / /__/ / / / |> -Roger Waters, Time /____/ \_/|/\_/ /____\___/ / \__________ |> (Dark Side of The Moon) ______________/