HAVS: The purpose of HAVS is to minimize the power consumption by dynamic adjust the optimal voltage, and limit the maximum voltage. The optimal voltage is actively determined for each frequency and temperature. HAVS actively adjusts the CPU voltage as the CPU frequency and temperature changes.
BFQ(Budget Fair Queueing) is a I/O Scheduler. BFQ is a proportional share disk scheduling algorithm, based on CFQ, that supports hierarchical scheduling using a cgroups interface.
BFQ generally performs better (for desktops) were perceived intractability (vs real throughput) is preferred. CFQ may unwittingly penalise a well written program with fast throughput, in favour of a slower program by virtue of its reliance on allocated 'throughput' vs BFQ's 'time' reliance.