![calculation in access calculation in access](https://i.stack.imgur.com/3jgaz.png)
![calculation in access calculation in access](https://i.ytimg.com/vi/H-mtENX4v6k/maxresdefault.jpg)
(By the way, in general, it is the responsibility of the original problem/exercise to make it clear the exact meaning of each given condition. It is a question about how we interpret the given conditions in the original problems. It is a question about how we translate the our understanding using appropriate, generally accepted terminologies. What is actually happening in the physically world should be (roughly) clear to you. There is nothing more you need to know semantically. This is the kind of case where all you need to do is to find and follow the definitions. So, the L1 time should be always accounted. Although that can be considered as an architecture, we know that L1 is the first place for searching data. However, that is is reasonable when we say that L1 is accessed sometimes. I agree with this one! You can see further details here.Ģ- As discussed here, we can calculate that using Teff = h1*t1 + (1-h1)*h2*t2 + (1-h1)*(1-h2)*t3 which yields 24. Then with the miss rate of L1, we access lower levels and that is repeated recursively. The logic behind that is to access L1, first. T1 means the time to access the L1 while t2 and t3 mean the penalty to access L2 and main memory, respectively.ġ- Teff = t1 + (1-h1) which will be 32. All are reasonable, but I don't know how they differ and what is the correct one.Īssume a two-level cache and a main memory system with the following specs: h1 = 80% t1 = 10ns L1 cache In order to calculate the effective access time of a memory sub-system, I see some different approaches, a.k.a formulas.