[CST-2] Comparative Architectures Question

[Chris North]

Hi,

Got a quick question

Am just doing some past tripos questions and have a problem with 99/8/4

In the third bit where it asks how the choice of page size/cache sizes
will affect the OS virtual memory system.  Which I can't really think of
anything for.  I know the number of bits required to specify a location in
the cache is 14 bits (and hencw we would expect a 50bit tag), and I know
for 8KB pages the offset within the page is specified in 13 bits (Meaning
the page is specified in 51 bits.  Now I know if we use 50 bits for the
tag this could mean that we get virtual memory aliases, but why don't we
just use 51 bits tag???????

Chris North