LGA 771 to 775 Adapter (MOD) – Run faster Xeon CPUs in a Core 2 Quad motherboard
If you're looking to extend the life of your LGA 775 system, there's an adapter available now that will let you install faster (and usually cheaper) Intel Xeon processors (LGA 771) into a Core 2 Quad motherboard (LGA 775). These Xeons cost a lot less and are basically identical internally to the high-end Core 2 Quad CPUs.
- List of LGA 771 & 775 CPUs + Current Prices
- Where can I get an adapter?
- Why would you want to do this?
- How does the adapter work?
- Minor modification to the LGA 775 socket is also required
- Motherboard Compatibility
- Recommended LGA 771 Xeon processors
- Tested motherboards
- Detailed instructions for completing this MOD
- Troubleshooting Problems
List of LGA 771 & 775 CPUs + Current Prices
The pages shown below should help with comparing Xeon prices and specifications. The first link has all the LGA 771 and LGA 775 CPUs combined into 1 table (sorted by price), and the others are the original uncombined pages.
- List of LGA 771 & 775 CPUs + Current Prices
- List of LGA 771 Xeon CPUs + Current Prices
- List of Intel Core 2 Quad, Extreme, & Xeon CPUs (LGA 775) + Current Prices
Where can I get an adapter?
Here's a current list of sellers (sorted by price). The sellers are located all over the world, so you should be able to find one that's close to you, and most of them will also ship worldwide.
Why would you want to do this?
Xeons are usually MUCH cheaper
For example, the Xeon E5450 is equivalent to a 3.0 GHz Core 2 Quad Q9650, and it currently costs about $19 (about $70 less than the Q9650).
Other good deals on LGA 771 Xeons include:
- 3.33 GHz X5470 for $38
- 3.16 GHz X5460 for $15
- 3.00 GHz X5450 for $15
- 2.83 GHz E5440 for $11
For detailed specs on all of the Xeons and a full list of current prices, take a look at this page.
Xeons also typically overclock better
Additionally, if you’re interested in overclocking (making the cpu go faster than its default speed), Xeon processors are usually made from the best silicon, so you can typically achieve higher overclocks with them.
Someone that recently did this mod successfully overclocked a Xeon X5470 from 3.33 GHz to 4.5 GHz on an ASUS P5Q PRO motherboard, so you can achieve really good results with these Xeons.
How does the adapter work?
The adapter is basically an electronic circuit on a sticker, and you place it on the Xeon processor (as shown in the picture below). This switches two of the pads on the bottom of the Xeon to make it compatible with a Core 2 Quad motherboard.
Xeons that are compatible with this adapter
This adapter is only compatible with LGA 771 Xeon processors. If you're unsure what LGA 771 means, it's the name of the CPU socket used in some Xeon motherboards. And in comparison, LGA 775 is the name of the socket used in Core 2 Duo/Quad motherboards.

Minor modification to the LGA 775 socket is also required
If you look at the LGA 775 socket in the picture below, you'll notice two tabs are circled in red. These tabs are there to stop you from installing a non-LGA 775 processor, and they'll need to be fully removed before you can install an LGA 771 cpu.
The tabs are pretty easy to remove if you have a sharp utility knife or box cutter (just be careful not to damage or bend any of the socket pins near the tabs).
Important: Make sure that you fully cut off each of these tabs. If they're not fully cut off, the processor may not align or seat correctly in the socket, which will stop it from making contact with all of the pins. If this happens, your system will likely fail to boot.
Once the tabs are cut off, you can use tweezers to safely remove the pieces from the socket.
The socket will then support LGA 771 or 775 processors (you can still reinstall your old processor if you ever need to).

- List of LGA 771 & 775 CPUs + Current Prices
- Where can I get an adapter?
- Why would you want to do this?
- How does the adapter work?
- Minor modification to the LGA 775 socket is also required
- Motherboard Compatibility
- Recommended LGA 771 Xeon processors
- Tested motherboards
- Detailed instructions for completing this MOD
- Troubleshooting Problems
1,453 Responses
we dont have adapters on this side of the world…. its too expensive to order. how about someone showing how an adapter is made . and explian why the adapter? please…
A que se refieren con e5450 ¿(co)?
checked motherboard compatibility and tested motherboards sections of this guide. My motherboard is HP 0aach chipset q35. MOTHERBOARD COMPABILITY page says its compatible with x3363 as well as q45 chipset BUT Tested motherboard page says q45 hp motherboard FAILED to boot on x3363. I’m so confused pls help me! Is my MB able to launch with x3363? Where can i find BIOS mod for it? Which one of x3363 OR x3360 is more reasonable to order (3360 is LGA775 but twice more expensive and has 5% lower ranks).