I noticed an error with several animated 3D target rings I have tried out.
The animation actually starts out looking for "animation0.tga" then "animation1.tga" etc . . .
Most I have seen have not used animation0.tga instead will use animation.tga. This causes TEXTURE.TXT to grow fast and slow down the EQ while targeting mobs/npc's/pc's.
You may want to look in your EQ directory and inspect TEXTURE.TXT to see if you have this issue.