Static energy minimization of 3D stacked L2 cache with selective cache compression

A Survey Of Architectural Approaches for Data Compression in Cache and Main Memory Systems

“…Further, compression reduces the footprint and memory requirement of an application and hence, it may allow transitioning the unused portions of memory into low power states for saving energy [8][9][10][11]. The reduced energy consumption and temperature may alleviate the need of thermal throttling, which provides headroom for achieving higher performance within same power and temperature constraints [12].…”

“…From above discussion, it is clear that the compression approach, although promising, is not a panacea and hence, many techniques use compression in a selective (or adaptive) manner [8,18,20,21,27,28,[34][35][36][37][38]. Table 1 presents a classification of different techniques.…”

“…Afterwards, the most probable elements are coded with [8, 10, 12, 16, 17, 23, 28, 29, 35, 40, 48-50, 52, 53, 56, 63, 64, 66, 78, 82, 83, 88, 93] Zero-content compression [14,35,41,50,52,57,62,78,81] Frequent value compression (FVC) [35,52,59,60,67,70] Base delta immediate (BDI) compression [16,23,35,48,51,63,83,93,94] LZ and variants [6,7,9,17,19,20,22 [8,12] Compression in GPUs [89,93,94] Use of compiler [9,21,43,44,72,73,93] fewer number of bits than those which are least probable. Thus, Huffman coding uses a variablelength coding scheme.…”

“…Park et al [8] use compression along with power gating to save leakage energy in 3D stacked last level caches. Their technique tracks the frequency of access to each cache line.…”