Hi Mmason121,

There are plenty of threads on this topic. According to one, the following CPUs were validated on that model:
HU585 Kentsfield Quad Core Kit, Q6600, 2.4GHz, 8MB, 1066FSB, B3
UP673 Kentsfield Quad Core Kit, QX6700, 2.66GHz, 8MB, 1066FSB, B3
WM543 Conroe XE Kit, X6800, 2.93GHz, 4MB, 1066FSB, B2

So you've got some decent upgrade options. Good luck!

The cost and availability of the processors will be suspect. IF you go higher than the Q6700 you would most likely need to have the liquid cooling H2C instead of the standard cooler. Now as to performance the cost of performance/CPU will be very small and in most cases you would not notice much difference from your current setup.

As to the video card anything over a GTS 450 or GTX 460 on the 750W supply will not again render you much more performance gain due to the chipset and the PCI 1.0 spec of the system.

Also keep in mind that an 7xx system over 3 yrs old is pretty much living on borrowed time. The system while having a great case design. Suffer immensely from the BTX spec to which the units were built. And the life expectancy of the motherboards averages 3-4 yrs. And once the board goes its really time to move on and up to a new system.

That would be the 720 motherboard as that is the only one you could use. 400 for a new board in this day and age for a  outdated design spec does not make much sense. For that price you can almost build a new i5 or i7 system.

there would also be some additional parts that would be needed to do the upgrade if you chose to go that route. The front panel i/o board needs to be replaced as well as the two cables that connect to it along with a new back panel plate as the layout of the two boards are a bit different and the 720 board no longer has a serial port.

Also your choice of processors does not change. the only major difference is the chipset used on the 720 board.

I hear that I can replace the motherboard with a newer one?  I had a chat with a dell rep, and they said I could upgrade it.  I wasn't sure if this was some older upgrade or if it was a newer motherboard. They said the  GT661 is the one I would be upgrading to.  Havent done research on it yet but all I know is they say its about $400

So I put the Conroe x6800, 2.93GHZ CPU in my XPS 710. Simply removing the old Conroe 1.8GHZ CPU and putting in the new one. The power comes on, but it doesn't Boot up. Fans work fine, but that's it????  I followed the advice you gave "mmason121"  Its a clean machine so i cant blame the dust or dirt. Is there something else I need to do other than swapping the CPU? I need to return this CPU within 14 days for full credit pleas let me know as soon as you can. Thank you for your time

Do you have the latest bios version?  You can try resetting the bios, power down, unplug the system. Press and hold the power button for 5~10 Sec. Open the case and remove the coin cell battery.  Wait about 10 mins and then reinstert the battery. Power up the system and see if it still gives the error.

There are also NVRAM jumpers on the motherboard for just that purpose (instead of removing battery) ... BIOS keeps a list of hardware that it manages.  Clearing the NVRAM clears that list and forces the BIOS to rebuild it.  This can often be required when replacing parts.

I have found the from personal experience with these system that that does not always work as advertised. but it is definatly a first shot try. ..

Thank you Dave. I'll give this a try. :-)

hmm I am not sure which route to go as of right now, my main thing is I don't have a lot of $ to spend so little upgrades to what I have is the best I can do for now.  Trust me I wish I could retire my 710 but I just cant afford a new PC at the moment.  You said these run the PCI 1.0 x16?  If I could at least beef up the video cards I might get some more time out of this thing before I really just need to go all out and upgrade.  My main concern is being able to handle RAW image format.  My PC does ok now with it and maybe Battlefield 3