Sorry i didn't see that math forum earlier..

Hello, I am having trobule with a problem and am wondering if anyone could help me understand.

This is for homework in my Computer Archtecture class at college.

Code:
I have a cache with access time of 4 nSec, 
compared to a miss time of 60 nSec. 
W/o the cache Mainmem has access time of 50nSec. 
Running a set of benchmarks w and w/o the cache indicated 
a speed up of 80%. What is the hit ratio...?

I have this formula

Code:
EAT =  H * AccessC + (1-H)* AccessM

H = hit rate
AccessC = cache access time
AccessM = main mem Access time
Can anyone possible help me ?

Thanks !!