it is hogging CPU like crazy; my mouse cursor is jumping erraticallly from one spot to another.
Houdini vs. Arena's Default engines

By the way, if you want to vote on the best chess engine, check out this topic.
In Arena it's a good idea to set the "Engine process priority in operating system" to "Lower than normal". You'll find that setting in the "Engine Management" window (press F11 to open this window), "Options" tab.
This will make Arena and other Windows applications a lot more reponsive when the chess engines are running full throttle.
Using "Lower than normal" priority will have no noticeable impact on the engines' performance, it will just make other applications more responsive.

how is noticeable defined?
IMO, with today's Rybka 4, and Houdini 1.5a out there as "simple downloads", yet possessing SO MUCH sheer calculating power, (oh, and it's "RHoudini" who made the setting recommendation!) "benchmarking" over 2,000 games at ratings topping out at just ABOVE 3000+, that even to ask "which is better" between Houdini 1.5a and Deep Rybka 4, while they are separated by a mere 57 ELO points, would very likely not even be noticeable to the likes of a Carlsen, and Anand, never mind players rated anywhere below 2800!
Like you and I. ;)
Peace!
BF/JS
I am currently running a tournement in arena where Houdini plays every engine that comes with Arena twice.