Beyond that, the new Pentium 4 570J processor does offer a little more than just another 200MHz, as that J lurking at the end of its model number suggests. Chipmakers often slipstream minor revisions of their chips into production over time, and this new stepping "E" of the P4 "Prescott" core packs two such enhancements.
First and foremost, Intel has given this new Pentium 4 support for the "no execute" bit, or NX bit, already found on AMD's K8 family of processors. (Intel calls its version the Execute Disable Bit.) This execution protection capability allows the CPU and operating system to work together to prevent the execution of code residing in certain areas of memory. This feature, which is supported by Windows XP Service Pack 2, can bring the clamps down on buffer overflow exploits that are commonly used to propagate worms and viruses. With the 570J installed, the NX bit feature shows up as a BIOS option (which we can enable or disable) on our Abit AA8 DuraMax motherboard.
The 570J also brings some relief for the power and heat problems in newer Pentium 4 processors in the form of an enhanced halt state. When idle, most operating system kernels send a "halt" command to the CPU to let it know to take a few cycles off. Entering halt mode can cool a processor considerably compared to running at full tilt. Intel says the new E-step Pentium 4 can idle between 10 and 15 degrees Celsius cooler than previous revs. Of course, that advantage only shows up when the CPU isn't terribly busy.
Let's have a gander at an excessive close-up of the P4 570J processor.
Like Intel's other recently introduced CPUs, this baby slips into an LGA775 socket, so it has no pins on its underside, only contact pads. That makes the CPU itself sturdier than a Nebraska cheerleader.