Table 1 shows estimates of the critical characteristics of the 14nm Knights Landing, compared to known details of the 22nm Knights Corner, Haswell, and Ivy Bridge-EP. The estimate of Knights Landing differ from the rumored specifications primarily in the capacity of the shared L2 cache, which is estimated to be 512KB, rather than 1MB. It is possible, although extremely unlikely that the shared L2 cache is 256KB. The analysis also incorporate several other critical factors which were not mentioned in any rumors, specifically cache read bandwidth and the large shared L3 cache. The L3 cache is estimated as eight times the size of the L2 caches or 144MB in the unlikely scenario that the L2 cache is 256KB, then the L3 cache is likely to be proportionately smaller.

via Knights Landing Details.