Transmission Control Protocol

I have heard it said that the TCP protocol becomes inefficient when used over high-bandwidth connections due to the window size being smaller than the amount of data transmitted in one cycle. Is there any truth in this? What about increasing packet size/sliding window size? I know that doing either or both of these things will require a larger buffer at the receiver end but that is in the hardware and the hardware should be designed to communicate over the maximum bandwidth that its interface supports… Anyone know the answer to this one?