Ok, I finally broke down last week and made the jump from dual core to quad, I also setup sli. My problem is I just ran 3dmark06 and I didn't even break 6000 marks. Below is my list of hardware let me know if you have any ideas on how to get my score up a little higher.
Actually it's kind of surprising you even got that high with them. Even my ol Radeon 3850 with everything at stock speeds gets 8700. If you're on a budget go with a 9600GT. Even a single 9600GT will give you much more performance than your 8500s. You can SLi a second one latter. If you can afford to spend a little more though try and get a 9800GT.