Unfortunately, VIS compiling is required as well as RAD. If you don't use them your maps will run in FullBright mode and won't look good. However if you just want to test a set of entities and how they interact (like Scripts), then you can save time by not running VIS and RAD.
If your map has complex brushes, lot's of light's, is large... or one of a million other things then it might seem like your computer is freezing, but in reality it isn't. If you run your "Task manager" you should see that hlvis or hlrad are still running. VIS and RAD Compiles can take a while. I have heard stories of DAY's... I have had personal experience with 13.5 hours.
Remember the "Ship" Skeeve?Stick with running VIS and RAD initially, as they can bring up some possible errors in the map as well..
Most of all "Be Patient" great maps are not made in 15 minutes
Also, there is no rule of thumb for compile times... Some maps will take longer than others. That's life, just hit Ctrl+Alt+Delete to see what tasks are running... bet you will find hlrad sucking up page files like there is no tomorrow.