Studio XPS 9000/435T, CPU upgrade

A faster Xeon X5680 which runs by default at 3.33 GHz (same series as X5675 which runs at 3.07 GHz) is confirmed to work in the Dell Studio XPS 435T/9000 at Geekbench 4 search (1 result).  So, the X5675 should be good to go in the 435T.

The Xeon X5675 should work in the 435T since other CPUs in the X56xx series have been demonstrated to work and higher frequency CPUs of other series work.  For details and a list of top CPUs that work or should work with the 435T see Dell forum thread here.

X5675 confirmed and working, even did a overclock and she is flying and playing fortnite.

3/4/19. Back from the dead. So I have. 435T sitting in my office and my son asked to have it for playing fortnite. I laughed and said I doubt we can play fortnite. So he challenged me to revive it and wanted to learn about computers. So I got my 10 yr old to research articles and see what's out there. It led us to this thread, I want to thank everyone who contributed and posted great info. We have upgraded the cpu to a Xeon x5675, New ram going in tonight. However, we are playing fortnite with the new cpu and the oem hd Radeon 5875 on medium settings. Who would have thought this 10 yr old computer and 10yr old kid could pull this off...lol Cpu ran $39 bucks on eBay from keystone memory. Now we are looking at the HD ra 8870 for $79 bucks. What a fun project and proves that with a strong community we can save money and have fun. I've been posting results on benchmark, keep an eye on our build!! Thanks again everyonefor all your knowledge!! https://browser.geekbench.com/v4/cpu/12234298

I went with the Xeon W3690 which works. Make sure you have the latest BIOS. 

Although I also just switch off The motherboard and went with an Asus Sabertooth X58 put it in a case I already had (Antec 300) & had to get a better PSU. 

Note: The Dell PSU could run it all normally with the Dell Board but could not handle the Asus Board. 

It started though with the Dell PSU (475w) but was not stable & would not see the 3 memory sticks right until I got the better PSU (600w)

I'm curious to know if you had to do anything special?  I just received my x5675 from ebay (waited a month for it to arrive!), plugged it in with new thermal paste, and unfortuantely no life to the computer, not even a beep code.  Just an orange power button.  Tried cleaning off the contacts with some alcohol, same result.

Worst part is, I threw my original 920 back in, and despite getting a bios screen, it won't boot at all into windows now, yet no errors.  I'm wondering if my motherboard somehow went from perfectly ok to toast in one afternoon.

Re: I just received my x5675 from ebay (waited a month for it to arrive!), plugged it in with new thermal paste, and unfortuantely no life to the computer, not even a beep code.  Just an orange power button. Worst part is, I threw my original 920 back in, and despite getting a bios screen, it won't boot at all into windows now, yet no errors. 

If pc can still boot w 920, that is good sign. You can always reinstall Windows in hdd.

assuming you have not done this, you may need to update bios to latest version in order to support 6 core i7 or Xeon in this model.

I made sure I was running the latest firmware A16 prior to this adventure.

Despite passing hardware tests, it looks like the motherboard is toast.  I think by some coincidence something else must have failed on the board.  It passes all hardware tests with the 920, just wont get into the boot stage, even with a USB boot media... 

Re: just wont get into the boot stage

that is unfortunate. It is able to pass POST but it would not proceed to preboot stage looking for a boot device?  Have you tried clear CMOs settings by CMOs jumper reset and replace CMOs battery with a new one ($1-2)?

refer to owner manual for jumper location (#29 in diagram p. 37/41)

No dice.  Booted without the battery, cleared CMOS using the jumper as well.  Looks like the boot sequence just never loads, yet all hardware is still passing tests.