I can't really speak for the AMD platforms as I'm not that well versed in them so I will leave that for someone else to answer. As for Z77, it is the older Intel Ivy bridge compatible motherboard platform as compared to Z87 which is Intel's Haswell platform. In general, Z87 has about a 10% performance increase over Z77. All Z87 compatible CPUs include hyperthreading whereas the Z77 platform generally doesn't, unless you are going for an i&, in which case Hyperthreading is also a feature. Z87 CPUs also have onboard voltage regulators which help regulate the voltage going to the CPU making the chips more energy efficient.