Does the hose diameter and overall hose length influence the performance of pneumatic tools?

I read somewhere that if you have more than 10' of hose; you need to increase the diameter.

Currently I am using a 20'1/2" diameter hose and the physical distance from the compressor to the tool is less than 10'. The compressor is a 60 gallon Husky (home Depot) compressor with a max output of 125 psi.

I am wondering what is going on, because my DA sander dies out quicker than I thought it should. Is the hose influencing my problem or is the compressor just not strong enough?

Thanks in advance for any comments!

Ross