Speeding up the visualization of a shapefile with more than one million of lines

[Luca Manganelli]

Hi, I have a shapefile with more than one million of lines (it's 42MB
in size). It's a cadastral layer.
I've split it in a map of 8x8 pieces. It's faster at low scales, but
if I want to see the entire map it's slow to render (about 5-6 seconds
on an Pentium IV 2,8 GHz server).
I would like to know is there's any way to speed up the rendering,
i.e., not rendering lines smaller than a factor.