## (Solved) Consider three different processors P1, P2, and P3 executing the same instruction set. P1 has a 4GHz clock rate and a CPI of 2. P2 has a 2.5GHz clock...

Consider three different processors P1, P2, and P3 executing the same instruction set. P1 has a 4GHz clock rate and a CPI of 2. P2 has a 2.5GHz clock rate and a CPI of 1.0, P3 has a 3GHz and a CPI of 1.2.

Which processor has the highest performance expressed in instructions per second?

If the processors each execute a program in 10 seconds, find the number of cycles and the number of instructions.

We are trying to reduce the execution time by 20% but this leads to an increase of 15% in the CPI. What clock rate should we have to get this time reduction?

Solution:

P1:Â  4 GHz, CPI = 2.0 â†’ 4GHz/ 2.0 = 2 x 109Â instructions/sec

P2:Â  2.5 GHz, CPI = 1.0 â†’ 2.5GHZ/1.0 = 2.5 x 109Â instructions/sec

P3:Â  3 GHz, CPI = 1.2 â†’ 3GHz/1.2 = 2.5 x 109Â instructions/sec

P2 has the highest performance at 2.5 GHz, CPI = 1.0 â†’ 2.5GHZ/1.0 = 2.5 x 109Â instructions/sec.

Â Â Â Â Â Â Â Â Â Â Â  P1:Â  Â Â  40 x 109Â cycles

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  20 x 109Â instructions

Â Â Â Â Â Â Â Â Â Â Â  P2:Â  Â Â  25 x 109Â cycles

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  20 x 109Â instructions

Â Â Â Â Â Â Â Â Â Â Â  P3:Â  Â Â  30 x 109Â cycles

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  25 x 109Â instructions

Execution time is reduced by 20% Ã  t=? s

Â Â Â Â Â Â Â Â Â Â Â  CPI is increased by 15%

Solution details:
STATUS
QUALITY
Approved

This question was answered on: Sep 05, 2019

Solution~000200039013.zip (25.37 KB)

This attachment is locked

We have a ready expert answer for this paper which you can use for in-depth understanding, research editing or paraphrasing. You can buy it or order for a fresh, original and plagiarism-free solution (Deadline assured. Flexible pricing. TurnItIn Report provided)

STATUS

QUALITY

Approved

Sep 05, 2019

EXPERT

Tutor