X38 versus X48 at 1,600MHz FSB

To continue the "so new it's not even available yet" theme, we have used a Core 2 Extreme QX9770 CPU. This is Intel's new Yorkfield-based 1,600MHz front side bus part that's due to launch sometime early next year.

The Core 2 Extreme QX9650 may already be available as Intel's first 45nm desktop CPU, but that only runs at 1,333MHz. As an Extreme Edition though, there's nothing stopping owners changing the multiplier-FSB combination from 9x333 to 8x400 and overclocking from 3.00GHz to 3.20GHz (you can do this on multiplier locked CPUs too, as Intel gives you access to multipliers lower than the default value - Ed).

In Intel's X48 press documents, the company claims a three to seven percent performance difference between 3.20GHz QX9770 (with its 1,600MHz front side bus and DDR3-1600) and the current 3.00GHz QX9650 (with its 1,333MHz front side bus and DDR3-1333). But is that three to seven percent performance difference masked by the memory and bus difference? How much does the new chipset contribute directly?

We look at the two almost identical Asus boards to see if there's any performance difference between X38 and X48 and a QX9770.

Memory Performance

It looks like the more mature BIOS on the X38 board has the slight advantage in synthetic results, even though we used the same BIOS settings and memory on both motherboards.