🚀 go-pugleaf

In article <BxtJvM.GBw@usenet.ucs.indiana.edu>, mdchaney@fractal.ucs.indiana.edu (M Darrin Chaney) writes:
>>In article <Bxnt6o.Jx0@mtholyoke.edu>, jbotz@mtholyoke.edu (Jurgen Botz) writes:
>>> 
>>> Nonetheless it's too expensive... 70ns 1Mb chips are selling for less
>>> than $2.50 per in volume... that works out to less than $25 for a
>>> 9-chip SIMM.  If your manufacturing cost is as high as $10/SIMM,
>>> that's still nearly a 300% markup.
> 
> There's another factor that our genious didn't take into account, that is,
> the speed of the memory.  70ns memory won't hack it on a machine that is
> running at 150-200MHz.  In case you didn't notice, 200MHz is a 5ns cycle,
> a bit smaller than, oh, say *70*.

I don't think _any_ of the high-density chips run on a 5 ns cycle -- I
think you have to go to a much more expensive and less dense technology
like ECL to get that kind of memory cycle time with current technology. 
Usually the memory is run at a lower clock rate than the CPU (that's what
the cache is for).  Even a 33 MHz 486 runs the CPU faster than commonly-
available memory chips (33MHz works out to a 30ns cycle time).

The point is well taken however;  I don't know the speed of the chips
in the Alpha memory arrays.  70ns is however a common clock rate for
the faster chips ... though I do know of some that are a bit faster.

> I know one 3rd party vendor, whose prices are significantly lower than DEC's
> on most products, just quoted me $6495 for 64MB of memory for the Sandpiper.
> DEC isn't too much higher than that, especially when you consider the price
> disparity in the DECstation-line memory cards.

That's a useful data point, it will be interesting to see how the prices
track the cost of other memory arrays once they are in full production.

Bruce C. Wright