Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!eru!luth!sunic!draken!d88-jwa
From: d88-jwa@nada.kth.se (Jon Watte)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Apple is dumping 120ns SIMMS into SE/30s
Message-ID: <2829@draken.nada.kth.se>
Date: 2 Feb 90 20:45:43 GMT
References: <15@hite386.UUCP> <7852@hubcap.clemson.edu> <2827@draken.nada.kth.se> <1463@husc6.harvard.edu>
Reply-To: d88-jwa@nada.kth.se (Jon W{tte)
Organization: Royal Institute of Technology, Stockholm, Sweden
Lines: 34

In article <1463@husc6.harvard.edu> siegel@endor.UUCP (Rich Siegel) writes:

And many others with him.

>In article <2827@draken.nada.kth.se> d88-jwa@nada.kth.se (Jon W{tte) writes:

>>A 16 MHz machine will not run at all if the SIMMS are 120 ns, since
>>the data won't be there when the CPU wants it.

>	Nope! yourself. Your calculator may tell you one thing, that the

>beg to differ; the memory is accessed at one wait state, and accesses are
>additionally bottlenecked by little things like bus arbitration.

Yeah, right, wait states. I stand corrected.

In fact, two cycles on a 16MHz machine uses ~125 ns. Plenty of time
there... Though, with lots of memory and poor ventilation in a cramped
SE/30, I still feel better with a little margin...

Yes, I'm paranoid, I even back my HD up, as often as every one or
two weeks !

>	If you were correct, then my 40MHz Mac II which has 4x100ns and
>4x120ns memory would not even start up.

That's, uh.... many wait states. :-)

Wonder why that's not mentioned in the ads ?

h+
-- 
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             h+@nada.kth.se  ==  h+@proxxi.se  ==  Jon Watte
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