This reply is lengthy but summarizes the issue.
This issue is for a Dell T-410 and I am trying to communicate with them regarding the upgrade. The support has been hit or miss as you can read below. It has taken me a month to get to this point.
My current Dell current processor is an FC-LGA1366 Socket: Intel Xeon Processor X5560 (4 core, 8M Cache, 2.80 GHz, 6.40 GT/s QPI)
Dell support on Twitter told me that they solved the problem of "upgrade path" by looking at the following manual: processor models are listed on page 25 and 26 of the technical guidebook. http://www.dell.com/downloads/global/products/pedge/en/PowerEdge%20T410%20Technical%20Guide.pdf
They concurred and said that I currently have a Xeon 5560. They also said that as long as the BIOS was updated to 1.3.8 or newer it will support the 5600 series processors, supporting what the Dell Technical Guide claimed was the best chip of: X5660 6 core, 2.80GHz, 95W, 12M, 6 6.4GT/s
However, with a little bit of research on the Internet, I found that the fastest FC-LGA1366 Socket, Intel Xenon chip is a: Xeon X5690 (6 cores, 3.47 GHz)
The comparison of the chips X5560, X5660, X5690, can be seen here:
Intel Xenon X5660:
The only difference that I can see is that the X5660 consumes 95 watts, and the X5690 consumes 130 watts, TDP. (Thermal Design Power (TDP) represents the near maximum power a product can draw for a thermally significant period while running commercially available software.)
Can I order the X5960 and use it with no issues? Will the current power supply support two of them?
Thanks for joining the Processor community.
Please bear in mind you own an Original Equipment Manufacturer (OEM) computer, therefore, this type of compatibility depends on the OEM.
Based on the computer specifications, it comes with an Intel 5500 chipset; please check the list of compatible processor for the chipset 5500.
If you noticed, the X5960 is not listed above. I recommend contacting Dell tech support for more information about processor upgrades: Chat Technical Support | Dell US