Computer organization speed up

Question

Consider a hypothetical system,which is used in application where program refers integers units and floats units.Floating units are enhanced so that they run 2 times faster,but only 90% instructions are floating point type.What isn the over all performance gain?

Comments

1/[0.1+(.9/2)]

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ye sure.....

actual time...

t/(0.9t/2  +0.1t)  ...=

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@Anu007 hs_yadav 

So here ,in the initial system without enhancement ,both Integer and floating units were taking same time?

I was solving like, 

Initial system, Integer unit time = x and    Float unit time =2y

 New system, Integer unit time =x and float unit time =y

Gain => $ (x+2y) /( .10*x+.90*y) $ // Can you tell what is wring with this equation.In your answer you have assumed that both inter and float units are taking same time in initial system.Is this assumption correct?