If my memory serves me correctly that motherboard has the nvidia intel/ 5xx sli chipset.
While different, nvidia Nforce based motherboards share the same front side bus chipset with the Dell hybrid intel/nvidia motherboards.
SO- I went to Nvidia and found the motherboard / processor matrix for the different NForce motherboard chipsets. I attached the list.
It came down to this If the procesor has a 1066 front side bus, it was compatible with the board.
If it had 1333 front side bus - it would not work.
This actually has to do with the manufacture of the processor. I understand it the 1066 mhz processors are built made with 65 nm technology.
The E7600 is made with 45 nm technology
SOOOO although you are at 1066, the E7600 may still be a problem.
I successfully ran a QX6600 on a XPS 700 board with the most recent Dell bios for the motherboard. that would be 5/31/2007 Version 1.4.1
I sold my 700 and now own a 720.
Hope this helps.
PS. I have tested quite a few video cards lately and I can tell you this -- The amount of level 2 cache is more important than the speed of the video card. I
have taken TOP video cards and put them on test motherboards. TOP of the line EVGA triple SLI 780 Nforce boards and with a mediocre processor they run marginally. I am not a gamer, but on the test bench with a Pentium D 3.2 800fsb 4mm cache Geforce 8800GTX , Geforce 9800 GTX and Radeon 2GB 4850 X2 give 3D Mark scores around 7000.
Put them in the Dell with a Q6600 2.4 with quad cores and 8mb cache and they jump up to over 12000.-14000 range
Previously tested them on a lesser motherboard with a Pentium D 2.8 800FSB 2 MB cache and got scores in the 4500-5000 range.
SOO draw your own conclusions. even though I have more than capable video cards the processors and the amount of cache proved to be the major factor in determining the performance.
All the boards had 4GB of memory