I had a Creative Geforce 256 SDR, and I was able to turn on AGP 4x and Sidebanding with their AGP utility. However I have a Elsa Erazor X2 DDR, but I dont know how to turn on the AGP sidebanding or AGP 4X
Try Powerstrip available at www.entechtaiwan.com to change these settings. I heard some people couldn't get it to work, but I know that it worked on a Prophet2 for me. The settings are kinda buried in the menu's, it's actully under diagnostics or something like that. Make sure your motherboard supports 4X first or you may have problems getting it changed back.