The Next Pentium 4

PCQ Bureau
New Update

The heat is on again in the processor war, and this time it's not clock speed, but many other factors. After AMD went out with its '64-bit to the desktop' campaign, it's now Intel's turn-and the answer seems to be the 6xx series of P4 processors. The key features built in to these processors include a 64-bit extension called EM64T (Extended Memory 64 Technology), SpeedStep and XD (eXecute Disable) technologies. There are five processors in the series (see table) with the highest end one known as the Extreme Edition.

Direct Hit!
Applies to: Desktop users
USP: Understand the four key features in the latest line of P4s from Intel

With EM64T, Intel has also entered the 64-bit race with AMD. Like AMD's offering, this one can also run 32-bit applications on a 64-bit OS. Plus, it can also run in pure 64-bit mode where it will run 64-bit applications on a 64-bit OS. So for all practical purposes, it's very similar to AMD's offering in the 64-bit space, and is therefore expected to work on the 64-bit OS versions from Microsoft, RedHat and Suse. One good thing is that it retains backward compatibility with Socket 775, meaning these processors will work on the 915 and 925 chipset-based boards. Moreover, L2 cache has been given a boost in the new processors to 2 MB, which is supposed to translate into much better performance. 

SpeedStep is not a new technology, as it's been around in Intel's mobile processor versions for notebooks. Now, it's also been introduced in the desktop P4 processors. Here, the processor will step down to a lower clock speed when lying idle, thereby reducing the power consumption. The moment the CPU utilization increases, the CPU raises the clock speed back to the maximum. This also helps in lowering the heat generated by the procesor. XD is Intel's initiative towards building security in the hardware to combat the growing security threats like virus attacks. This feature helps control buffer overflows, the most common technique used by security threats. XD creates a separate memory area in RAM for program execution and the data (data storage area) related to it. If some malicious program tries to access and modify data in this storage area, the processor prevents it from executing. This technology will prevent malicious programs from snooping into unused portions of the memory. You, however, would still need an anti-virus tool or anti spyware to protect from regular malware. AMD also has a similar technology in its 64-bit processors, known as Enhanced Virus Protection.With the new P4 series, Intel has also joined the 64-bit race to the desktop with AMD. Add to that Microsoft's Windows XP 64-bit edition RC2, which is available for download (360 days trial version) and you just might see a shift to 64-bit to the desktop sooner than you can imagine. 

P4 64-bit processors' specs


Side Bus (MHz)


1066 3.73
660 800 3.6
650 800 3.4
640 800 3.2
630 800 3

Note: all processors have L2 cache and are manufactured with the 90 nm process.

Sushil Oswal