Hi,
This is a good question. I believe we'll need some more information from you to make a determination. We need the Tech Specs on the Desktop PC with the LGA775 Motherboard; for example, Dell E520, HP Pavilion 1420cn, etc. Then we'll need to know the Chipset information. You can download
SI Sandra or SPECCY (from piriform.com) for free and run to determine this, if you can't see it in the PC's BIOS information upon bootup.
Generally, however, It appears that you would need to use a LGA775 Motherboard that has an embedded Intel Chipset such as the G31 or G33 on it to do so. There are about a dozen Motherboards listed as compatible by Intel ARK (see here:
http://ark.intel.com/products/33910...6M-Cache-3_00-GHz-1333-MHz-FSB#@compatibility).
The real issue isn't form factor (socket compatability) or even Chipset compatability however. The real issue is
HEAT DISSIPATION. Laptop CPU's are not designed to handle the much greater heat generated by a more powerful processor and or Chipset and or GPU Chipset or discrete Video Card that is generated by a Desktop of similar make and year in a laptop. This means that even IF the E8400 core 2 Duo CPU chip fits into a Motherboard, you will be
MORE limited on the number and type of applications that you would be able to run on that Desktop using a CPU chip from a Laptop Motherboard. For example, any kind of online Gaming applications and CAD programs such as AutoCAD, could easily burn up that CPU inside the Desktop socket! However, if you're just going to use this Desktop to logon to the Internet to check E-mail, facebook, and write a few Word documents and print them; that's probably not going to be a problem.
**Remember, on your Tech Specs, we'll need the EXACT Make/Model of your embedded Video Chip (say ATI, NVIDIA, etc.) or a discrete Video Card (say ATI GeForceMX440; 64MB) and it's Shared RAM memory capacity.** While waiting for this information, I'll add one more thing. Generally, Laptop CPU chips are designed to handle lower performing temps and CPU/Chipset/GPU stresses than their Desktop CPU chip cousins. Practically this limits what you can do with this Desktop PC as I mention above. And, if this is a Desktop PC you need to keep, and it not going to be easily replaceable, I personally wouldn't try it. It's quite likely there are other design differences that we are not aware of and could burn up that Desktop PC Motherboard beyond repair!
If this is going to be a
"lab-rat" experiment for the heak of it, and you really don't care whether or not the Desktop PC is damaged for good, you can certainly try it. Regardless of the replaceability of this Desktop PC, I might consider looking on ebay for a backup Desktop PC Motherboard identical to the one you are intending to sacrifice for this experiment and buy it to have on hand or at least save it and print it out if you do need it later on. Should be around $75 or less on ebay as it's an older processor.
Keep in mind one last thing, if you do more the E8400 to the Desktop PC and burn it up; don't expect it to ever work in the laptop you took it from originally again!!
This type of upgrade is really only a 1-way trip if it doesn't work.
Best of luck,
<<<BIGBEARJEDI>>>