- #1
SpiffyEh
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Homework Statement
a) If the new floating-point speeds up floating-point operations by, on average, 2x, the floating-point operations take 20% of the original program execution time, what is the overall speedup(ignoring the penalty to any other instruction)?
b) Now assume that speeding up the floating-point unit slowed down the data cache access, resulting in a 1.5x slowdown or 2/3 speedup. Data cache accesses consume 10% of the execution time. What is the overall speedup now?
c) after implementing the new floating-point operations, what percentage of execution time is spend on floating-point operations? What percentage is spent on data cache access?
Homework Equations
Amdhal's law: speedup = 1/((1-fraction_enhanced)+(fraction_enhanced/speedup_enhanced))
The Attempt at a Solution
a) I used amdhal's law and solved part a and ended up with 1.235 speedup
b) I understand what it's asking but I don't understand how to use amdhal's law with two different speedup/slowdowns. Is there a way to do this?
c) I have no idea how to solve this part