2 is enough - 1186 (15.7%) 3 is golden-mean - 200 (2.7%) 4 seems optimal - 2159 (28.6%) 6 or 8 is the best - 594 (7.9%) 4-core Nehalem and multi-threading are the most future-proof! - 1094 (14.5%) Everything depends on workload and micro-architecture - 2312 (30.6%)