Thread: Write-back cache

Write-through and Write-back cache

I am student and I want to know the difference between write through and write back cache. Please give me details information about this.

1) I think write-through cache, distinguish changes made to cached data are concurrently created in original copy, where in write-back not. The write back cache is able to do quickly compare to write through cache. But in few points, differences between cached and original data could cause problems, and so, write through caches must be utilized.

2) Write-Through cache: In this, after writing is completed in cache memory, main memory is updated too instantly to maintain consistency.
Write-Back cache: In this, after writing is done in cache memory, flag bit as dirty bit is set. And when this value is needed it is modify by bit check, and if it is set then value is taken to major memory.