How well does the x850XT PE AGP card respond to changing the bus speed? I just upgraded from a 9800xt that I was running an 80mhz AGP bus with. However Ive had other cards that wouldnt work if there was a 1mhz change in bus speed. I can lock the bus with the mobo, but I noticed with the 9800xt it was performing better at 80mhz then 66mhz. What are other owners running for a bus speed? I just wanted to get a base idea before I started to tweak it.