You could buy mine and just find out for yourself.
$115 shipped and it is yours.
First off, I assume you are saying a 45/4500, since I think the smallest 3000 psi is 47ci. I actually have never used my 45/45 since I got it in a trade. If I had to guess, I would say around 750-850. I think I get about 1200 from my 68/45.