How laggy is the texture glow function?

K I have a large amusement park, it's a demo lot for my shop "Carnivale" and I have been trying to get my lag down as much as I can. I dropped a bunch of scripts, and just floated it a few hundred metres up to try and combat the lag from my neighbors. At least client based lag. But how laggy is the glow function. My builds have a lot of selective glow. Maybe 25% of a 1/4 SIM. So a lot. But I am debating turning it off on the demos if it will save on lag. Does anyone know? I know it's just a function of the client side. But does excessive use of glow cause a lot of lag?