High speed lines can have steeper profiles than normal lines because the greater kinetic energy and loco power makes them less troubled by slopes. Eg this compares the profiles of the old Paris-Lyon route with LGV Sud-Est:
Even better. Though this particular example compares the difference between a general-purpose railway line designed for steam traction and a passenger line for electric ones.
http://www.railfaneurope.net/tgv/images/misc/profilln1.jpg