Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!crdgw1!rpi!uupsi!sunic!liuida!isy!ingemar From: ingemar@isy.liu.se (Ingemar Ragnemalm) Newsgroups: comp.sys.mac.misc Subject: Re: Speeding up a IIsi Message-ID: Date: 17 Feb 91 15:00:42 GMT References: <60103@eerie.acsu.Buffalo.EDU> Sender: news@isy.liu.se (Lord of the News) Organization: Dept of EE, University of Linkoping Lines: 47 feinberg@acsu.buffalo.edu (john a feinberg) writes: >Ever since I got my IIsi a couple of months ago, all I ever did was leave it >in 256 colour mode. However, I tried out a game called Star-Roids, and after >noticing that it was simply too slow, I tried it's suggestion of putting the >computer in black & white mode. The game went a *lot* faster! I then tried >out a lot of other programs in black and white mode. Sure enough, the computer >seems to be up to five times faster than in 256 colour mode! So if you're one >of those out there who feels the need for speed, and haven't really had the >common sense to try this out before (like me!), try out the black & white mode! There are two reasons for the slowdown you experience in 8-bit mode. 1) The amount of data written to the screen is 8 times more. Nothing you can do about that, except using less pixels per pixel. However, this seems *not* to be the major problem... 2) The IIsi has a strange memory configuration. Basically, the first 1 meg is on the board, and it is used as video ram *but also as general ram*. This means that when the work is made in this memory, the CPU and video both must access the same memory, and therefore wait for each other. The measurements I've made imply that it is slowed down by almost 50%! (You say 5 times. That sounds like too much to me, unless they are *very* graphic intensive.) Two solutions to 2): a) Find a setup where your application is, for any reason, not placed in the video ram. For me, it works just fine if I use 4-bit mode. It is also ok with 8 bit and UniFinder. (Why?) Note that I experience no speed difference between 4-bit and 1-bit mode! b) Buy a video card. Expensive, but it solves the problem. (I don't have one, but my brother reports no slowdown for his Mac, with a 21" monitor.) c) Load some application before the one you want to see run fast. The first might take the "slow "memory, and the next "fast". Works for me, at least... A larger system heap might help too. >I recently traded my MacRecorder & miscellaneous stuff for an Apple video >card, >which I hope will substantially speed things up, since b&w white, >to be frank, sucks. Does anybody have a IIsi with a separate card? >Does it help? Yes, it does help - at least, so they say. -- Ingemar Ragnemalm Dept. of Electrical Engineering ...!uunet!mcvax!enea!rainier!ingemar .. University of Linkoping, Sweden ingemar@isy.liu.se