1
GATE CSE 2024 Set 2
Numerical
+2
-0.66

A non-pipelined instruction execution unit operating at 2 GHz takes an average of 6 cycles to execute an instruction of a program P. The unit is then redesigned to operate on a 5-stage pipeline at 2 GHz. Assume that the ideal throughput of the pipelined unit is 1 instruction per cycle. In the execution of program P, 20% instructions incur an average of 2 cycles stall due to data hazards and 20% instructions incur an average of 3 cycles stall due to control hazards. The speedup (rounded off to one decimal place) obtained by the pipelined design over the non-pipelined design is ________

2
GATE CSE 2024 Set 1
Numerical
+2
-0.66

The baseline execution time of a program on a 2 GHz single core machine is 100 nanoseconds (ns). The code corresponding to 90% of the execution time can be fully parallelized. The overhead for using an additional core is 10 ns when running on a multicore system. Assume that all cores in the multicore system run their share of the parallelized code for an equal amount of time.

$$\text { The number of cores that minimize the execution time of the program is _______. }$$
3
GATE CSE 2021 Set 1
Numerical
+2
-0.67

A five-stage pipeline has stage delays of 150, 120, 150, 160 and 140 nanoseconds. The registers that are used between the pipeline stages have a delay of 5 nanoseconds each.

The total time to execute 100 independent instructions on this pipeline, assuming there are no pipeline stalls, is ______ nanoseconds.

4
GATE CSE 2021 Set 1
Numerical
+2
-0.67

Consider the following instruction sequence where register R1, R2 and R3 are general purpose and MEMORY[X] denotes the content at the memory location X.

 Instruction Semantics Instruction Size (bytes) MOV R1, (5000) R1 ← MEMORY[5000] 4 MOV R2, (R3) R2 ← MEMORY[R3] 4 ADD R2, R1 R2 ← R1 + R2 2 MOV (R3), R2 MEMORY[R3] ← R2 4 INC R3 R3 ← R3 + 1 2 DEC R1 R1 ← R1 – 1 2 BNZ 1004 Branch if not zero to the given absolute address 2 HALT Stop 1

Assume that the content of the memory location 5000 is 10, and the content of the register R3 is 3000. The content of each of the memory locations from 3000 to 3010 is 50. The instruction sequence starts from the memory location 1000. All the numbers are in decimal format. Assume that the memory is byte addressable.

After the execution of the program, the content of memory location 3010 is ______