David Boyes <[EMAIL PROTECTED]>
>
> > Although the article did have issues, I'm most disconcerted
> > with some of the bang-per-buck comparisons (one of the
> > charts showed a mid-range SUN performs at 300% that of the
> > z/900 at only %18 of the cost... and that was a *mid-range*
> > SUN!)
>
> He's comparing apples and Brazil nuts. It depends a lot on the
> application -- there are cases where the Sun is the right answer, many where
> it's not. You have to profile the application.
Wonderful! I'd be very delighted to have someone set-me-straight
on these points...
>
> > If a mid-range SUN is only 18% of the cost of a (slower) mainframe,
> > it will make selling mainframe Linux (vs. SUN Linux) a lot harder.
> > Granted, the RAS facilities of the mainframe are nice, but for
> > 18% of the cost... if you had to, you could buy 3 or 4 SUN boxes,
> > keeping most of them in the closet as "spares" and still be
> > cheaper.
>
> I would argue that the figures in the article do not include the whole
> picture. For a *single* application, he may be close. It's when you deploy
> application n+1 and n+2 that the difference/advantage becomes apparent. He's
> falling into the usual trap of doing TCOs based only on hardware price --
> that isn't the whole story, and he's not including cost of operators, floor
> space, etc. Our studies indicate that the breakdown for TCO is nominally:
>
> 20-23% hw/sw cost
> 37% people
> remainder facilities (power, HVAC, floor space, network bandwidth, etc)
>
> It's kind of weird that people focus on the smallest portion of the problem
> while ignoring the other 70+% of the problem...
Hmm... that could be very true...
But - he's comparing one mid-range sun to one z/900. Seems like
the 37% people and remainder facilities would be the same in both
of those. One sun should be just about as much work/power as one
z/900.. in fact, I'd expect one mid-range sun to be a little lower
on the power/HVAC requirements.
So - if we accept that, then really we're talking about %18 percent
of that 20-23% hardware figure... right?
I may be just a little "slow" on the up-take here, so bear with
me while I walk through this... I _really_ want a nice compelling
argument here.
Let's say that the mainframe TCO costs $100. The hardware costs would
be $20, the "rest" of the cost (the part that's the same between
the alternatives) is then $80.
So - the Sun box would be 18% of the z/900 hardware cost.
Thus, if the z/900 TCO is $100, the Sun TCO would be $83.6 - a savings
of 16.4%.
Granted, a savings of 16.4% is much better than a savings of 82%, but
16.4% is still quite a significant savings.
Am I understanding this correctly? Or, have I missed the boat somewhere?
So - then the argument would be that for 16.4% more, you can get
all of the RAS of z/900 hardware, vs. the mainframe box. Is that
a fair statement?
Please don't get me wrong - I'm a big proponent of Linux on the
mainframe; our company has quite a substantial investment in seeing
it succeed. I'm just trying to get together a fantastic response
when asked the question myself, which does come up from time to time.
What better place to get a reliable answer?
Then, we need to understand (and address?) performance concerns. This
was all under the assumption that the z/900 runs as fast, and hopefully
faster, than the mid-range Sun. And, with this "back-of-the-napkin"
calculation, there are several other issues to consider (virtualization
technology for one.) And, as you mention, this ignores the very good
point regarding testing your application "in the environment."
- Thanks! -
- Dave Rivers -
--
[EMAIL PROTECTED] Work: (919) 676-0847
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