COMP251 – Computer Organization and Architecture Fall 2009 ...


 COMP251
–
Computer
Organization
and
Architecture
 Fall
2009
 
 Homework
#7
 Memory
Systems
 
 1.
Compute
the
effective
memory
access
times
for
the
systems
with
the
 specifications
given
below.

 a.
 An
L1
Cache
with
7
ns
access
time
and
a
hit
rate
of
87%
and
main
memory
 with
88
ns
access
time.
 b.
An
L1
Cache
with
7
ns
access
time
and
a
hit
rate
of
87%,
an
L2
Cache
with
30
 ns
access
time
and
a
hit
rate
of
98%
and
main
memory
with
88
ns
access
time.

 You
should
assume
that
all
data
contained
in
the
L2
cache
contains
a
copy
of
all
of
 the
data
in
the
L1
cache
plus
some
additional
data.
 
 2.
Essentials
of
Computer
Organization
and
Architecture,
Chapter
6,
#2
(p.
320).
 
 3.
Essentials
of
Computer
Organization
and
Architecture,
Chapter
6,
#4
(p.
320‐1).
 
 4.
Essentials
of
Computer
Organization
and
Architecture,
Chapter
6,
#6
(p.
321).

For
 part
b,
assume
that
the
cache
is
initially
empty.

Also,
instead
of
computing
the
hit
 ratio,
compute
the
hit
rate
(i.e.
the
percentage
of
memory
accesses
that
result
in
 cache
hits).

Add
the
following
part
c
to
the
question:
To
which
cache
set
would
the
 following
address
map:
0x13FA.
 
 5.
Essentials
of
Computer
Organization
and
Architecture,
Chapter
6,
#12
(p.
322).
 
 6.
Essentials
of
Computer
Organization
and
Architecture,
Chapter
6,
#16
(p.
324‐5).
 
 7.
Define
the
terms
spatial
locality
and
temporal
locality.

Explain
as
clearly
as
 possible
how
cache
leverages
the
natural
spatial
and
temporal
locality
that
occurs
in
 programs
to
improve
system
performance?
 
 8.
Define
the
term
thrashing
as
it
relates
to
virtual
memory.

Discuss
the
tradeoffs
 that
exist
between
the
potential
for
thrashing
and
complexity
of
implementation
of
 the
paging
and
segmentation
approaches
to
virtual
memory.