The letter "J" - indicates a processor has Execute Disable Bit capability. Enabling Execute Disable Bit functionality requires a PC with a processor with Execute Disable Bit capability and a supporting operating system. Check with your PC manufacturer on whether your system delivers Execute Disable Bit functionality. Introducing the boxed Intel® Pentium® 4 processor with HT Technology in the new LGA 775 package manufactured on Intel’s industry-leading 90nm process technology. Combined with the new Intel® 925X, 915P and 915G Express Chipsets† this new Intel® desktop platform enables new technologies to power today's applications and emerging PC entertainment such as high definition video and audio.
Note: To help meet the required processor thermal specifications, an internal ambient temperature at or below 38º C is required. It is strongly recommended to use a Thermally Advantaged Chassis (TAC) based on Chassis Air Guide 1.1 or equivalent. With these new processors, Intel has introduced processor numbers as a means to identify the various features of the Pentium® 4 processor in the LGA775 package.