From: macuser@milton.u.washington.edu (Hung Le)
Newsgroups: comp.sys.mac.misc
Subject: Re: Information on: The IIvi, IIvx, and Performa 600
Date: 16 Aug 92 23:40:34 GMT
Organization: University of Washington, Seattle

In article <1992Aug16.210017.1816@risky.ecs.umass.edu> breck@ganzer.ecs.umass.edu () writes:
>Someone emailed to me (Liam Breck):
>> in comp.sys.mac.misc you write:
>> > The IIsi's only advantages are slightly better CPU speed (not a big
>> > enough difference to notice in real time use, but you will notice the
>> > disappointing screen redraw speed) and the ability to plug in Nubus
>> > cards, again, not an issue because the LCII is a very popular machine,
>> > so there are a lot of cards for its PDS (processor direct slot).
>>
>> You want to justify this? The si uses a 32 bit bus, not a 16 bit bus, so is
>> about twice as fast. Same reason an SE/30 is twice as fast as an LCII. Also
>> an LCII has max memory of 10MB. That doesn't leave much room for expansion.
>> I have 8MB on my SE/30 right now and plan to go to 20MB in a month or so.
>> I'd be pissed off if my machine maxed out at 10MB.
>
>This is a common misconception.  Actually, the IIsi is about 28%
>faster, which is not enough to notice in most real-time applications.
>When doing something very CPU-bound, you might notice.  That is to
>say, if you usually complete a coffee break while compressing a large
>archive with an LCII, you will have a bite of doughnut and sip of
>coffee to go when the same task finishes on a IIsi.  :-) This 28%
>difference in speed is mostly accounted for by the difference in
>processor speed beetween the two machines -- 16MHz vs. 25MHz.  The
>*IIci* is something like twice as fast as the LCII since it's clock
>speed is 33MHz.  The bandwidth of the memory bus is really not
>critical in personal computers, 'cause other bottlenecks hold things
>up before the bus width does.  For instance, the 80386 is only 4%
>faster than the 80386sx, which has a 16-bit external memory path.
>It's the same in the case of the Macs; you'll find that the original
>Mac II is only 4% faster than the original LC (both 020s at 16MHz).
>
>A really critical issue, though, is screen redraw time, since most
>real-time apps (word processors, drawing apps, the finder, etc.)
>redraw the screen a lot.  The LCII uses the latest Apple on-board
>video standard, which includes dedicated, dual-ported VRAM.  The same
>stuff that the Quadras use, only pared down for the LCII.  It's very
>fast compared to using the main memory for video (the IIsi and IIci do
>this).  You can speed up video on the latter machines by making your
>RAM cache huge, but that's another subject, see one of the columns in
>the current MacWorld (sorry, forget which one) for more info.
>
>Another point about video...  Since the LCII can use a low cost VGA
>monitor (I got a Trinitron screen for $350) it really lets you save on
>the monitor.  To get the same quality on a IIsi, expect to shell out
>the bucks!
>
>The 10MB limit on the LCII's memory expansion is unfortunate, but not
>unacceptable.  I have 8MB in mine, and run a whole heap of concurrent
>applications and I haven't run out of memory yet!  If I was going to
>use Quark and Photoshop at the same time to work on some layout, I
>would buy a IIci (or one of the future Macs) and a lot of memory, not
>a IIsi and same.
>
>So, when the whole story's told, the LCII is a better machine
>price/performance wise than the IIsi.  The only reason I can think of
>to buy a IIsi is if you absolutely have to use a Nubus card.  But
>since the LC(II) is the best selling Mac ever made, I don't expect
>you'll find a lack of cards for it...
>-- 
>Liam Breck     breck@zonker.ecs.umass.edu
>



excuse, but the IIci is only 25Mhz, not 33Mhz!