Better way to indicate “a large amount of ”

A Wikipedia article tells us that:

A problem is regarded as inherently difficult if solving the problem requires a large amount of resources, whatever the algorithm used for solving it.

What is a more elegant, and perhaps more correct, way of expressing the notion “a large amount of ” in a context like this?

EDIT after comments: Maybe what bothers me is the the large amount followed by plural resources. I like a large amount of butter on my morning toast; and I like having a lot of books around; but I’m not so sure I’d say I like having a large amount of books here.

FINALLY I changed the sentence to read

A problem is regarded as inherently difficult if its solution requires significant resources, whatever the algorithm used.

Solution 1:

If you're just looking for a one-word synonym, you could try significant resources.

If you want to express that the amount is larger than necessary, or onerously large, you could try excessive resources.

Solution 2:

I don't really see anything 'inelegant' about a large amount of, but if you just want something shorter, substantial or considerable would fit the bill.

Solution 3:

It seems the theory in question is concerned about the proportion of available computational resources available to devote to any one problem. In this context, disproportionate resources would work well. Since disproportionate could also mean too few, you may need to qualify it as a disproportionately large amount of resources, but I think the simpler phrase remains clear from the context.