HP introduces 64-bit Prescott desktop
 

TIN FIRM Hewlett Packard has started selling PCs which use 64-bit microprocessors from Intel that support the iAMD64 instruction set.
The XW4200, which HP describes as a workstation but may just as well be a PC, uses PCI Express graphics from Nvidia, Windows XP or Linux, and support for up to four gigabytes of error correcting DDR-2 memory at 533MHz, or non error correcting DDR-2 memory at 400MHz.

The Prescotts are at speeds of 3.4GHz and 3.6GHz with EM64T supported.

http://www.theinquirer.net/?article=17608