We have the same security cam setup as green tree, with about 14 cameras.....and got similar results with the i7 having moved up from the base i5, that was also pegged continusously.
As far as CPU benchmarks are concerned, lack of RAM should make little difference in scores.
"Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin