Contents
- 1 How do you calculate average memory access time?
- 2 How does memory hierarchy affect access time?
- 3 How do you calculate effective access time?
- 4 What is effective memory access time?
- 5 What are the five hierarchy of storage devices or memory hierarchy?
- 6 Which of the following is the slowest in the memory hierarchy?
- 7 What is the formula for hit ratio?
- 8 What is effective access time?
How do you calculate average memory access time?
average memory access time = hit time0 + miss rate0 * (hit time1 + miss rate1 * miss penalty1 )
How does memory hierarchy affect access time?
As we move from top to bottom in the Hierarchy, the capacity increases. Access Time: It is the time interval between the read/write request and the availability of the data. As we move from top to bottom in the Hierarchy, the access time increases.
What is memory access time and how it measured?
(1) Memory access time is how long it takes for a character in RAM to be transferred to or from the CPU. Fast RAM chips have an access time of 10 nanoseconds (ns) or less. Disk access time is always given as an average, because seek time and latency vary depending on the current position of the head and platter.
How do you calculate effective access time?
To find the effective memory-access time, we must weigh each case by its probability: EAT(effective access time)= P x hit memory time + (1-P) x miss memory time. effective access time = 0.80 x 120 + 0.20 x 220 = 140 nanoseconds.
What is effective memory access time?
The ‘effective access time’ is essentially the (weighted) average time it takes to get a value from memory.
How can I improve my memory access time?
Reducing Memory Access Times with Caches
- Fetch instruction.
- Decode instruction and fetch register operands.
- Execute arithmetic computation.
- Possible memory access (read or write)
- Writeback results to register.
What are the five hierarchy of storage devices or memory hierarchy?
The five hierarchies in the memory are registers, cache, main memory, magnetic discs, and magnetic tapes. The first three hierarchies are volatile memories which mean when there is no power, and then automatically they lose their stored data.
Which of the following is the slowest in the memory hierarchy?
Memory Hierarchy
| Speed | Memory |
|---|---|
| Fastest | Cache |
| RAM | |
| Slowest | Disk |
What are the two main components of access time?
Access time consists of latency (the overhead of getting to the right place on the device and preparing to access it) and transfer time. The term is applied to both random access memory (RAM) access and to hard disk and CD-ROM access.
What is the formula for hit ratio?
To calculate a hit ratio, divide the number of cache hits with the sum of the number of cache hits, and the number of cache misses. For example, if you have 51 cache hits and three misses over a period of time, then that would mean you would divide 51 by 54. The result would be a hit ratio of 0.944.