Re: How can the system be bumped-up to the next evolution of RAM-processing..?



On 11/01/2011 08:08 PM, Marko Vojinovic wrote:
On Wednesday 02 November 2011 01:56:13 Linda McLeod wrote:
[snip]
Why is there RAM..? Why can't the OS
run its RAM off'n the hd..?

RAM exists because I/O of a HD is waaay too slow. You can get a feeling just
how slow it can get when you open too many apps simultaneously, thus
exhausting available RAM and making the OS use the swap partition for extra
memory. It's *painfully* slow, the machine becomes practically unusable, and
it's a complete waste of cycles of today's fast processors.

Even the I/O of RAM itself is fairly slow compared to the typical modern
processor. That's why processors now have a built-in cache (which is basically
a smaller amount of RAM on the processor chip itself), in order to speed up
execution of programs and calculations.

You might then ask "why the processor designers don't put all RAM on the
chip?" Because it would be too big, geometrically. In order to make the
processor work on a 2GHz frequency or such, the chip surface must be small
enough to keep everything in working conditions. Otherwise you run into out-
of-sync problems, uneven heat and voltage distribution problems, and all sorts
of stuff that would make the processor fail. So the bulk of RAM must be
separated, on their own chips, and communitace with the processor via the
motherboard, which is again quite slow, due to its size and other reasons.

Uhm, Marko, I think Linda was trying to be facetious. Good info from
you, though. :-)
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