CPEN 4700 FINAL EXAM BASED ON PREVIOUS TESTS
QUESTIONS AND CORRECT ANSWERS
How to determine cycle time of a processer? - ANSWER 1/frequency x 10^9, units is
seconds if left in notation
Suppose you know the advertised performance for a CPU is 6.3 GFLOPS(6300
MFLOPS).How many floating point instructions does it execute in one cycle? What is
CPI? - ANSWER multiplying the number of instructions per cycle with the clock rate
(cycles per second given in Hertz) of the processor in question.(6300 x 10^9)(cycletime)
CPI is 1/FPI
While Running a program on this system you have 270 million cache hits and 8 million
cache misses. What are the hit and miss rates if this program? - ANSWER Hit/total*100
Miss/Total *100
WHat is the maximum memory bandwidth of the DDr4 1600 memory?(Use Correct
transfer rate) - ANSWER bits of bus /8bytes / cycle time B/s if no move decimal
1600*10^6*64*1/8 = 1.28*10^10B/s 12.8 GB/s
How long does it take to read the first bytes from RAM (Use CAS Latency) - ANSWER
CasLatency x (1/ clockspeed x 10^6 cyc/s)
12*(1/800x10^6)=1.5x10^-8=15ns
Neglecting other Cache levels and any other parts of a memory system and only utilizing
the L2 and DDR4 memory described above, what is the effective average memory
across time while running thr program from question 3? - ANSWER EAT(effective
access time)= P x hit memory time + (1-P) x miss memory ti
(.9712x(4(0.67ns)+(0.0288)(15)=3.02
, A system with 8 GB of RAM has 16 MB cache with 64-byte refill lines. How many lines are
in thecache? What are the sizes of the tag, index, and byte fields (in bits) if the cache is
direct mapped? 8way set associative mapped? Fully associative mapped? - ANSWER
GB->2^33 if GB
2^20 if MB
2^10 if KB
exponent = 33
Mb to cache, INDEX is found by .
64B= 2^6=6 bytes
15,left over is tag
if 4-way, replaces first exponet with 2, 8 replace with 3,16 is 4 fully there is no index
6 bytes, 15(each line has 15), 11-tag
A method of improving the performance of a system but at the expense of higher power
consumption-ANSWER Overclocking
This below hardware invention from the second generation still forms the basis for all
modern computers - ANSWER Transistors
The connectiions in computer system which join the major parts together - ANSWER Bus
In a multi level cache where the lines go when evicted from a lower level - ANSWER
Victim Cache
In a virtual memory system wher the address translation info is stored - ANSWER page
table
This memory organization uses relative addressing to locate data - ANSWER SAM
In a cache memory, the unit of data that is moved into or out of cache. - ANSWER Valid
QUESTIONS AND CORRECT ANSWERS
How to determine cycle time of a processer? - ANSWER 1/frequency x 10^9, units is
seconds if left in notation
Suppose you know the advertised performance for a CPU is 6.3 GFLOPS(6300
MFLOPS).How many floating point instructions does it execute in one cycle? What is
CPI? - ANSWER multiplying the number of instructions per cycle with the clock rate
(cycles per second given in Hertz) of the processor in question.(6300 x 10^9)(cycletime)
CPI is 1/FPI
While Running a program on this system you have 270 million cache hits and 8 million
cache misses. What are the hit and miss rates if this program? - ANSWER Hit/total*100
Miss/Total *100
WHat is the maximum memory bandwidth of the DDr4 1600 memory?(Use Correct
transfer rate) - ANSWER bits of bus /8bytes / cycle time B/s if no move decimal
1600*10^6*64*1/8 = 1.28*10^10B/s 12.8 GB/s
How long does it take to read the first bytes from RAM (Use CAS Latency) - ANSWER
CasLatency x (1/ clockspeed x 10^6 cyc/s)
12*(1/800x10^6)=1.5x10^-8=15ns
Neglecting other Cache levels and any other parts of a memory system and only utilizing
the L2 and DDR4 memory described above, what is the effective average memory
across time while running thr program from question 3? - ANSWER EAT(effective
access time)= P x hit memory time + (1-P) x miss memory ti
(.9712x(4(0.67ns)+(0.0288)(15)=3.02
, A system with 8 GB of RAM has 16 MB cache with 64-byte refill lines. How many lines are
in thecache? What are the sizes of the tag, index, and byte fields (in bits) if the cache is
direct mapped? 8way set associative mapped? Fully associative mapped? - ANSWER
GB->2^33 if GB
2^20 if MB
2^10 if KB
exponent = 33
Mb to cache, INDEX is found by .
64B= 2^6=6 bytes
15,left over is tag
if 4-way, replaces first exponet with 2, 8 replace with 3,16 is 4 fully there is no index
6 bytes, 15(each line has 15), 11-tag
A method of improving the performance of a system but at the expense of higher power
consumption-ANSWER Overclocking
This below hardware invention from the second generation still forms the basis for all
modern computers - ANSWER Transistors
The connectiions in computer system which join the major parts together - ANSWER Bus
In a multi level cache where the lines go when evicted from a lower level - ANSWER
Victim Cache
In a virtual memory system wher the address translation info is stored - ANSWER page
table
This memory organization uses relative addressing to locate data - ANSWER SAM
In a cache memory, the unit of data that is moved into or out of cache. - ANSWER Valid
