A few interesting things happening here:- 4,005 534x7.5

Do a direct comparison... same FSB, same memset timings, just try with 8x multi and 9x
Not particularly clear, at least, comparing :-
3,900 7.5x520Mhz @2.40B 5,5,5,12
to
4,160Mhz 8x520 520Mhz @2.40B 5,5,5,12

FSB..Multi...Read.....Write
520...7.5 ..10,664...10,895
520...8.0 ..10,814...10,989
% ...100.86%..101.41%

BUT FSB Coimparison seems to Highlight shift better:-
E8200 7.5x500 @3.33D = 1667DDR 7-6-5-18

E8200 7.5x510@1360Mhz DDR3
FSB..Multi...Read.....Write
510...7.5 ...9,813...10,278
520...7.5 ...9,723...10,528
101.96%. ..99.08%.102.43%

luck