I have Dimension 9150 which is 945P. It runs only 2 core, no Hyper-Threading.The chipset is is stripped down via BIOS.
Go to Dell-> all support->manuals, select xps for more specifications on Your PC.
Dell staff told me that Dimension/XPS MB were customized for Dell by Foxconn.
Unfortunatelly, Foxconn do not update their specs for new processors I'm affraid. But You might e-mail them for advice.
Spent all weekend on this and there is not label/barcode on the motherboard, (believe me, I tore that thing apart looking for it). I have an email into Foxconn to see if they can help and also contacted Dell Support and they told me that I have to stay in the 800Mhz catagory, but can go up to a 3.6Ghz processor. So I am guessing I can be safe with the 945 or 950. I'm still researching. Thanks for all your help.
it is good customers are pushing Foxconn for processors upgrades. Dimension/xps are both foxconn, since 2005 i have
not seen any BIOS changes which would address new procesors.
So in the end it is possible the new processor will not run at all or as expected.
Their WEB site has not been fixed up for days, the Compatilibity button will display "cannot load the page".
Note sspec may be overlapping, so Foxconn is the only source of qualified info.
I have been very busy lately, sorry for late contribution.
I said sspec should be labeled on MB. If it is not, than follow the manual for Your PC and lift off the cooler.
It seems Dell dont use any paste, which gleues cooler/CPU. Intels coolers do not do either, there is a thin sheet of aluminium in between.The cooler paste will ruin( tear a hole) in it next time You remove the cooler!
The sspec is on the CPU, five letters followed by revision# in braces.
How sspecs combines I do not know yet.