I know there are lots of posts about C2D in an XPS 600, but they seem to all be for 800 series of processors. So basically, what are the thoughts on a Conroe C2D working in my XPS with a Pentium D 945? The mobo is a nForce4 SLI X16 and it can handle up to 1066 FSB. Also, I have a friend that has a C2D (I think it might be an Allendale or Wolfdale), I might be able to get him to let me try it in my XPS if I get some thermal compound. What are the chances that if it doesn't work it would damage his CPU? I'm more worried about his stuff than mine, my XPS is 6 years old already.
According to the spec sheet you are stuck with a Pentium D being the best processor that Dell can handle.
Intel® Pentium® Extreme Edition Dual-Core with HT Technology - (3.20GHz,800MHz FSB,2MB Cache)
Intel® Pentium® D with Dual-Core Technology - Up to 840 (3.00GHz,800MHzFSB,2MBCache)
Intel® Pentium® 4 with HT Technology - Up to 670 (3.80GHz,800MHzFSB,2MBCache)
It is possible but the 840 and 945 are both Pentium D chips. It's would not damage anything to try. It just would not boot if the Core2 chip did not work. If any Core2 chip did work it would likely only be a Conroe or an Allendale. A Wolfdale has a 1333FSB.