Sounds like you have your wireframe options set too high!
Right side of the screen - the RESOLUTION icon. Set this to about 16 for static and selected items.
This always happens when you have a lot of objects in your scene.

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All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...