That is a wonderful question. Unlike a computer, the capacity of the brain can not be measures only in terms of the amount of data it can store or the number of computational operations it can perform per second.
When it comes to raw data capacity or number of operations per second the best human brain can perform, the computer would seem to win every time.
When we look at the kind of operations that can be performed by even the average human brain that every the most mighty super computer has yet to be able to do we must look beyond capacity.
The finely tuned and well educated human brain is capable of defining and operating of types of problems that computers show no capacity to undertake. Humans seem to be able to design a wide range of unique solutions to a range of problems that it is still difficult to even adequately express in any computer language.
Computers had do mathematical operations on large collections of numbers at amazing speed with no requirement for rest. Some can even be programmed to draw on the recorded results of previous attempts to solve similar problems which resembles what we call learning. When it come to writing programs to attempt to resolve the many kinds of human problems that do not easily lend themselves to being expressed in any of the many computer languages, the best computer scientists acknowledge that despite their capacity and computational speed, even the best computers still seem rather incompetent to even express the kind of problems that most human brains can, with experience, understand and sometime develop many alternate solutions to deal with those problems.
To get to the root of your original question, given adequate time to interpret, categorize and encode the pieces of information and how they relate to each other, the capacity of the brain to retain and retrieve such information continues to exceed all apriori estimates. In other words, we continue to be amazed at how much information the brain can hold of things it understands.
Computers can store huge amount of numbers that mean nothing at all to the computer.