clipka <nomail@nomail> wrote:
> What's the processor clock of your P4?

  3.4 GHz.

> What's the typical processor clock of a modern multi-core CPU?

  Certainly not 340 MHz.

> The modern Multi-Core CPUs win mainly due to...

> - optimizations regarding caches, pipelining etc.
> - providing multiple cores to run programs on

> With a PRNG test suite, however, none of these bring any advantage. There are no
> difficult-to-predict branch instructions; virtually no additional data to fetch
> into the caches; no parallel threads to distribute the workload; all the CPU
> has to do is to braindeadly execute one single thread of pure arithmetic
> instructions.

  That doesn't really explain an entire order of magnitude of difference in
speed. This is especially so because the Pentium4 line is notoriously crappy
at things like bit shifting (because they removed the fast shift barrel from
the P4 line for whatever reason, and reintroduced it later in the Core line,
AFAIK).

  If a Core2 Duo runs simple integer operations at 1/10th the speed of
my Pentium4, I really don't want a Core2 Duo.

  However, I still suspect there's something else going on here.

> I'm not too much surprised that in this case the bottleneck is sheer GHz power -
> the only thing that hasn't been improved at all since the P4 (to the contrary!).

  I would find it rather disappointing if processors had gone 10 years
backwards in integer speed (and in fact floating point speed as well,
because the floating point tests were also significantly faster in my
computer).

-- 
                                                          - Warp

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