LRU and many other newer replacement algorithms. This is achieved by using reuse distance as a metric for dynamically ranking accessed pages to make a replacement decision. LIRS effectively address the limits of LRU by using recency to evaluate Inter-Reference Recency (IRR) for making a replacement decision. In the above figure, "x" represents that a block is accessed at time t. Suppose if block A1 is accessed at time 1 then Recency will become 0 since this is the first accessed block and IRR will be 1 since it predicts that A1 will be accessed again in time 3. In the time 2 since A4 is accessed, the recency will become 0 for A4 and 1 for A1 because A4 is the most recently accessed Object and IRR will become 4 and it will go on. At time 10, the LIRS algorithm will have two sets LIR set = {A1, A2} and HIR set = {A3, A4, A5}. Now at time 10 if there is access to A4, miss occurs. LIRS algorithm will now evict A5 instead of A2 because of its largest recency. Adaptive replacement cache (ARC) Constantly balances between LRU and LFU, to improve the combined result. ARC improves on SLRU by using information about recently evicted cache items to dynamically adjust the size of the protected segment and the probationary segment to make the best use of the available cache space. Adaptive replacement algorithm is explained with the example. AdaptiveClimb (AC) Uses recent hit/miss to adjust the jump where in climb any hit switches the position one slot to the top, and in LRU hit switches the position of the hit to the top. Thus, benefiting from the optimality of climb when the program is in a fixed scope, and the rapid adaption to a new scope, as LRU does. Also support cache sharing among cores by releasing extras when the references are to the top part of the cache. Clock with adaptive replacement (CAR) Combines the advantages of Adaptive Replacement Cache (ARC) and CLOCK. CAR has performance comparable to ARC, and substantially outperforms both LRU and CLOCK. Like ARC, CAR is self-tuning and requires no user-specified magic parameters. It uses 4 doubly linked lists: two clocks T1 and T2 and two simple LRU lists B1 and B2. T1 clock stores pages based on "recency" or "short term utility" whereas T2 stores pages with "frequency" or "long