Detail Texture and the lower end

[Yeha]

Spring dynamically switch to lower terrain resolution when the system is under heavy load to maintain framerate.
When you quickly change the camera to another location on the map there is a good chance that part of the map is no longer in memory and needs to be recreated, this can create a very brief fps slowdown which causes spring to use a lower resolution of the map for a short period of time.
This is why the map sometimes apears to be blurred for a short moment when changing view.

[IMSabbel]

Turning off mip-mapping will make the game run faster.

They improve caching by the GPU a lot, so it would usually make it faster to have mipmaps enabled.

Thats very depending on your gpu and the locality of the texture usage. If you are potentially short on texture memory, the thrashing will be the bigger factor.

[Das Bruce]

very brief fps slowdown which causes spring to use a lower resolution of the map for a short period of time.

Anything upto a 5 second pause.