Why is mapping so slow?

Factors affecting mapping performance

If you are having problems with slow map drawing in the interactive mapping application, the techniques described here may help.

There are several factors influencing map redraw speed, including:

the number of layers enabled,
how many layers have labeling turned on,
the rendering complexity of the layers,
map scale,
available network bandwidth, and
server load.

Use a minimal set of layers while getting oriented

Each map layer that you turn on adds overhead to the preparation of the map. While you are positioning your map, enable only those layers you need to orient yourself. Once you have your scale and extent about right, turn on the additional layers you wish to see on the final map.

Turn off labeling where possible

Labels have a relatively high performance overhead, so leave off the labels while you get your map set up.

Turn off slow layers

Certain mapping layers are much slower than others, and the rendering speed of a layer isn't always what you would expect. For example adding labeled 50m contours to a map will slow down map drawing much more than adding the 1:100,000 topo layer, even though the topo layer is visually far more complex; it includes contours and far more! The difference stems from the way the data is stored on the server. Some layers, like the topo maps, have been preprocessed to make them fast to redraw. For some layers that isn't possible or hasn't been done yet.

Here are some of the layers we know are slow:

Fire hazard,
Sea, rivers, lakes
50m contours
Vegetation cover,
Cadastre

Avoid stepping quickly through map scales

Each time you change the map scale by moving the scale slider up or down, your web browser will requests 9 or more individual map tiles from the server. The server will finish creating each of those tiles even if you change map scales again before those tiles are returned.

If you know you want to move several scale steps, save yourself some time by clicking directly on the map scale you want instead of using the plus and minus buttons to step incrementally through the scales.


Home News Help Apply For Access Create Maps Links About Contact Us Email: Password: create account reset password	Back to help Why is mapping so slow? Factors affecting mapping performance If you are having problems with slow map drawing in the interactive mapping application, the techniques described here may help. There are several factors influencing map redraw speed, including: the number of layers enabled, how many layers have labeling turned on, the rendering complexity of the layers, map scale, available network bandwidth, and server load. Use a minimal set of layers while getting oriented Each map layer that you turn on adds overhead to the preparation of the map. While you are positioning your map, enable only those layers you need to orient yourself. Once you have your scale and extent about right, turn on the additional layers you wish to see on the final map. Turn off labeling where possible Labels have a relatively high performance overhead, so leave off the labels while you get your map set up. Turn off slow layers Certain mapping layers are much slower than others, and the rendering speed of a layer isn't always what you would expect. For example adding labeled 50m contours to a map will slow down map drawing much more than adding the 1:100,000 topo layer, even though the topo layer is visually far more complex; it includes contours and far more! The difference stems from the way the data is stored on the server. Some layers, like the topo maps, have been preprocessed to make them fast to redraw. For some layers that isn't possible or hasn't been done yet. Here are some of the layers we know are slow: Fire hazard, Sea, rivers, lakes 50m contours Vegetation cover, Cadastre Avoid stepping quickly through map scales Each time you change the map scale by moving the scale slider up or down, your web browser will requests 9 or more individual map tiles from the server. The server will finish creating each of those tiles even if you change map scales again before those tiles are returned. If you know you want to move several scale steps, save yourself some time by clicking directly on the map scale you want instead of using the plus and minus buttons to step incrementally through the scales.