On a microcoded machine, megahertz numbers are totally useless. They're useless in
general anyway because an instruction may take one, or two, or many clock cycles.
With level-two and level-three cache and internal queueing an Intel microprocessor can
take as many as 13-17 clock cycles from fetch to execution of some instructions.
RISC-based processors, such as the current IBM PPC chip, average about three.
Microcoded processors, who knows?
Which would you prefer for your daily commute? A car that does 60 miles per hour, but
can only travel on a road that is 90 miles to your job, or a SUV that does 30 miles an
hour but can travel cross-country 10 miles to your job? Relying on megahertz numbers
implies you get there quicker in the faster car.
Use the Best! Linux for Servers
Macintosh for Graphics
Palm for Mobility
Windows for Solitaire.
Gordon W. Wolfe, Ph.D. VM & Linux Systems Support
Enterprise Servers, The Boeing Company (425)865-5940
> ----------
> From: McKown, John
> Reply To: Linux on 390 Port
> Sent: Wednesday, December 10, 2003 9:06 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Technical Specs
>
> As you said, a meaningless question. I don't know if IBM even publishes this
> information. However, just for fun, Phil Payne's site
> (http://www.isham-research.com/mips_z800.html) rates a 2066-001 at 192 MIPS.
> I am fairly sure that a -OLF runs at the same MIP rating. I do know that our
> -0A2 is rated at 259 MIPS (or 149 MIPS/CPU) but the IFL on that machine
> still runs at "full speed" or 192 MIPS. I think that the "slow down" for all
> the "subspeed" processors is done by putting some sort of "wait state" code
> in the machine's microcode. I.e. the processor really does run at 192 MIPS,
> but it appears to run slower due to this "wait" at the end or beginning of
> each instruction.
>
> This question is right up there with the one our ops manager wanted to know:
> "How do I monitor the z800's CPU temperature like I do the Intel servers?"
> Answer: "You don't"
>
>
> --
> John McKown
> Senior Systems Programmer
> UICI Insurance Center
> Applications & Solutions Team
> +1.817.255.3225
>
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>
> > -----Original Message-----
> > From: Jason Herne [mailto:[EMAIL PROTECTED]
> > Sent: Tuesday, December 09, 2003 11:28 AM
> > To: [EMAIL PROTECTED]
> > Subject: Technical Specs
> >
> >
> > We are running a 2066-OLF (z/800 Linux only model). Can
> > anyone point me
> > to some IBM documenation that tells me the speed of the processor in
> > Mhz? I understand that this metric means very little but
> > someone higher
> > up in the management chain would like to know :-)
> >
> > - Jason Herne ([EMAIL PROTECTED])
> > Clarkson University Open Source Institute
> > z/Server Administrator
> >
>
>
