"Invisible" <voi### [at] devnull> wrote in message
news:480cb7fe$1@news.povray.org...
>
> I was aware that these days the RAM is about 20x slower than the CPU,
> and that's why the CPU has to have a cache the size of a small planet to
> achieve any performance whatsoever.

Cache misses are the bane of modern processors. It's one reason why the
hyperthreaded CPUs performed really well for some scenarios and badly for
others (eg SQL server). The two virtual cores share L1 cache, so if one is
moving lots of data around, the other one suffers repeated cache misses.
Dual cores have seperate L1 cache and sometimes seperate L2 cache as well.
Sometimes the L2 is shared, but has usage limits for the two cores.

I can't remember which specific CPUs had which architecture. It's been
several months since I last looked at this.

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