My system, i7 930 and gtx 470 got 18.5k bone stock. So since the i7 860 Turbos up a bit higher, 20k sounds about right.
With my i7 930 overclocked to 4.011ghz I score ~25K, 3DMark06 is bound by the cpu by today's standards because of the low resolution we test at.
3DMark Vantage, or the new one coming out should give yo a much better snapshot of your computer performance. FYI the 6870 is slower then the gtx 470, at the very most equal to.