X-bit labs

Desktop Intel Pentium 4 “Prescott” Processors Can Enable 64-bit – Rumour.

Category: CPU

by Anton Shilov

[ 01/04/2005 | 01:54 PM ]

A Taiwan based web-site reported a rumour claiming there is a possibility to enable 64-bit capability on Intel’s latest Pentium 4 microprocessors in LGA775 form-factor using a mainboard BIOS update. While the information may be correct, it is currently highly-unlikely that such operation will becomes popular.

“Lately there have been some rumours about some special BIOS that can ‘turn on’ the 64-bit [capability] on the [Intel Pentium 4] “Prescott” processors. I have made some enquiries and it seems that there are works in progress [that] are still in ‘alpha’ stage,” a claim over the web-site OC WorkBench states. 

Intel’s Extended Memory 64 Technology also known as 64-bit Extension Technology or IA32e lets Intel’s 90nm microprocessors for desktops, workstations, 2-way and 4/8-way servers to execute specially-written 64-bit code while maintaining absolute compatibility with today’s 32-bit applications.

Previously it was believed that all Intel Pentium 4 processors “Prescott” in LGA775 packaging would sport EM64T, but Intel denied such claim. Intel said it would ship Prescott processors with 64-bit capability for 1P applications only to system integrators requesting such microprocessors for their servers and workstations. Although all Prescott CPUs, including Intel Pentium 4 and Celeron D, are 64-bit from micro-architectural standpoint, processors supplying for retail channels as well as for typical desktops have their 64-bit capability disabled.

It is unclear, how Intel suspends 64-bit capability on its chips and whether it is possible to enable it on the level of BIOS, a small program that commands computers’ mainboards.

Historically Intel disabled certain functionality on its chips in a way that it was nearly impossibly to enable it using BIOS or software tweaks. For instance, sources close to the company said virtually all Intel Pentium 4 processors at 130nm fabrication process featured Hyper-Threading technology, long before the company officially unveiled its first HT chip Intel Pentium 4 3.06GHz in late 2002. While some could enable the Hyper-Threading on various chips that did not support it officially, there were reported only a few number of such cases.

Leading workstation makers, such as HP, currently offer PCs with Intel's 64-bit Pentium 4 chips installed with Linux operating system installed. Intel is expected to officially enable EM64T on its desktop products when it releases Intel Pentium 4 processors 600-series in late February, 2005.