62 views

Work done by me :for write it will always be $100ns$

Now for read :$20+0.2*100=40$
Total =$0.7*40+0.3*100=58$

closed as a duplicate of: Cache Access Time

closed | 62 views
+2

in qsn given is lookaside cache, parrallel accessing will be followed, i.e for read: $0.8*20 + 0.2*100 = 36$

what you have done for read, i.e $20 + 0.2*100 = 40$(this is for look through cache.)

0
0
in a cache is working in look-aside mode, then parallel accessing will be done rather than hierarchical access.
0
Oh so its like simultaneous access? Where if its hit then its find by if its miss we access Both at the same time !

Average memory access time =  Time spend for read + Time spend for write

= Read time when cache hit + Read time when cache miss
+Write time when cache hit + Write time when cache miss

0.7*(0.8*20 + 0.2*100) (Simultaneous read as look aside mode is given)

+ 0.3*(0.7*100 + 0.3*100) (as write through policy is used)

=25.2 + 30 = 55.2

https://stackoverflow.com/questions/34001002/look-through-vs-look-aside

by Active (1.1k points)
selected