Revamped Mobile Pentium 4 Will Not Get Security Capabilities

Intel Will Not Enable NX bit in Mobile Prescott Products

by Anton Shilov
06/20/2004 | 03:41 AM

Intel Corp. released a white-paper that indicates the company’s plans to transit its Mobile Pentium 4 processors to a new core stepping. The new chips will emerge this Fall, but unlike the desktop brethren will not contain any enhancements in terms of functionality, primarily the so-called XD technology.


Faster Mobile Pentium 4 Chips Enroute

Intel said the transition from D-0 to E-0 revision of the Mobile Intel Pentium 4 core will bring certain optimizations that are likely to enable further speed enhancements. While no significant changes are expected, the central processing units will change CPU signature and S-Spec code and will require updated BIOS.

The recently announced Mobile Intel Pentium 4 Processors are designed for larger-sized notebook PCs, also known as “desktop replacements”, typically featuring large screens, full-size keyboards and multiple drives. Mobile Intel Pentium 4 processors 538, 532, and 518 are based on the Prescott architecture and feature 1MB L2 cache, SSE3 technology and the HyperThreading. The chips brought no clock-speed increases over predecessors, even though they are made using thinner 90nm process technology compared to predecessors, and are available in 3.20GHz (538), 3.06GHz (532) and 2.80GHz (518) speed-bins.

Thermal design power (TDP) of the new “Prescott” Mobile Pentium 4 processors at the speeds of 2.80GHz, 3.06GHz and 3.20GHz is 88W. Intel also told notebook makers that future direction of TDP is 94W, seriously more compared to 76W thermal design power of previous generation Mobile Pentium 4 chips produced using 130nm process technology.

No Security, 64-bit Capabilities Expected

In early June 2004 Intel disclosed plans to transit its 90nm desktop Pentium 4 processors to a new stepping that will deliver a number of new techniques discussed by Intel earlier this year. The new capabilities Intel plans to include into its desktop products are the so-called AAC technology that adjusts performance depending on load in order to maintain low heat dissipation and quiet operation of personal computers as well as XD technology – aka Execute Disable Bit (NX bit) – a certain flag that determines whether instructions can be executed from the page. The new processors were not expected to dissipate less power than current chips.

Mobile processors typically do not require technologies like AAC or Cool’n’Quiet since they feature more advanced methods to shrink power consumption, such as SpeedStep.

Adding the XD technology might provide the Mobile Pentium 4-based notebooks an additional security feature, something that competing Mobile Athlon 64 have had for quite some time now. One of the reasons why Intel does not enable the XD is that Mobile Pentium 4 processors feature mPGA479 packaging, but Intel states that only LGA775 chips will activate the Execute Disable Bit.

Intel also did not indicate availability of its 64-bit EM64T capability in the forthcoming Mobile Pentium 4 processors.