Crossfire wrote:
O Plameras was once rumoured to have said:
Robert Collins wrote:
Holy shit! You are soooo off base here its not funny. 'More than one
thing per clock cycle' -> What do clock cycles have to do with
parallelism? Nothing.
Clock cycles has everything to do in the analysis of CPUs. It is the
basic measure of CPU performance.
Wrong. The basic measure of performance is the time required to
complete an operation, not the length of a clock cycle. Clock rate
and operation speed are very orthogonal things.
I will not try to convince you otherwise. I am repeating what I know from
Intel documentations.
In fact you'd be a lot better as a programmer if you do understand
clock cycles. For example, codes expend clock cycles when data are
moved around memory; no clock cycles are expended when data are
moved around certain registers. In this view, you'd learn what
codes in C to avoid and what codes to use.
Actuallly, he knows better than you do.
Is it not true what I am asserting above ? You have no explanation just
a personal
and 'cowboy' observation.
I am repeating what I know from Intel documentations. And this has
nothing to do
with comparing you or him or me. This has everything to do with clariyfing
what Intel says and my understanding as to what they are telling us
users of their
CPUs. You have your own ideas; good luck with your ideas.
10 years ago, most machines couldn't even fetch data from L1 cache in
a single clock cycle -- some of the earier PPCs were a good exception
there, but the x86 certainly was not a fast machine when it comes to
average cycles per op.
This is not an explanation of clock cycle as far as CPU performance.
(I can't speak for now - nor do I care to - but I'd be amazed if intel
has mysteriously revamped their processor to complete all operations
in a single cycle though - all of a sudden, all the collected x86
optimisation technique would go to waste).
Aha ! So you have'nt perused the x86 documentations. Strongly recommend you
do and let us know your understanding.
O Plameras
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