If I were specing a machine for HN, naively, it would be a competition between a Xeon "enterprise" CPU with huge cache and memory bandwidth (interleaved up) and a gaming/desktop CPU with maxed-out single-core performance. Xeons can do single-core turboboost now, so E5-2690 which goes up to 3.8GHz is probably the best bet, but a desktop i7-3970X 4.0GHz might be an option if you don't need ECC (which also gets you slight speed improvement on memory).