🚀 go-pugleaf

      I have a question concerning caches.  Currently,
caches are used, either in uniprocessors, or multiprocessors,
because the time a microprocessor takes to execute an
instruction is much smaller than the time to reference
main memory.  Thus, a cache is used to match the speed
difference (the cache is usually as fast as the microprocessor).

      Thus, it is evident that a cache can very dramatically
improve the throughput of a microprocessor.  For multiprocessors,
much research is being conducted to find efficient algorithms
for multi-cache consistency.

      Multi-cache consistency problem arises when, say a
block of data resides in the caches of processors A, B, and
C.  Then, if processor B decides to write to that block,
it must inform A and C that their copies of the block are
no longer valid.

     My question is, then, with the current improvements in
memory chips (ie. faster access, and greater densities), does
anyone forsee a time in the distant future (> 3 or 4 years)
that the speed of say, a 1Mb chip will be comparable to that
of say a 1Kb ECL chip used in current caches?

     In other words, will all the research being conducted
for the cache coherency problems be a waste?  Could the
research done for multi-cache coherency be applied elsewhere?

Thanks.

             Hemi Thaker

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