so my radiant is getting laggy, an is making it harder to place models an objects etc. when moving things its choppy an skips alot. is there a way to increase the usable resources for radiant, like how much ram is used for it or something?> 

so my radiant is getting laggy, an is making it harder to place models an objects etc. when moving things its choppy an skips alot. is there a way to increase the usable resources for radiant, like how much ram is used for it or something?>

I am sure there is some things you can do on the hardware end but, its much easier to just use the the hide functionalities built into Radiant including cubic clipping and Layers. I used to design maps on incredibly low end hardware and in order to get no lag I would just hide the sections of the map I was not working in using layers.

could you link me a tut for this, or explain to me how to hide sections into layers?

could you link me a tut for this, or explain to me how to hide sections into layers?

Cubic Clipping should be enabled by default and it just culls entities that are out of a set range for your 3D view.

To enable it go to:
View ---> Cubic Clipping (all the way at the bottom of the drop down menu)