File:Intel Xeon E5450 (with 775 mod).png

English: Intel Xeon E5450 "Harpertown", which has been modified to fit in the LGA775 socket. Several prerequisites are required for this to work:

• The mainboard and its chipset have to support the equivalent Core 2 Quad with respect to lithography (i.e. 65 or 45 nm generation), FSB speed and TDP.
• The BIOS may have to be patched with the microcodes for Socket 771 Xeons.
• A commercial mod sticker applied in the right position for electrical compatibility.
• Mechanical compatibility with LGA775. This can be achieved by altering the socket itself (two tabs have to be removed), or by cutting notches (top and bottom) into the processor PCB as seen on this example.

The 771-to-775 mod is mainly performed for cost reasons. At the time of writing, used Xeons together with an inexpensive sticker shipped from China are generally much cheaper than high-end Core 2 Quads on the second-hand market, making this an attractive value-for-money proposition for Socket 775 systems still in use. For instance, the E5450 has the same specifications as the Q9650 and is the final upgrade path for low-end mainboards limited by the chipset (max. 1333 Mhz QP), VRM design (max. 95 W TDP) or both. Faster Xeons are available, but not every board can safely handle the faster front-side bus of 1600 Mhz QP and higher power requirements of 120-150 W.