The Logical Consequence

New developments on the PC market usually take a long time to break through. The last significant evolutionary step started in 1985, when Intel launched the 80386 processor – the first 32-bit CPU. However, it took some time for the 386 to replace its predecessors the 8086 and 80286 – in 1986, PCs with 8086 were still generating mass business in the trade. It also took a long time for Microsoft’s Windows 95, a purely 32-bit operating system, to be available to the wider market. The next stage in computer development looks as though it will follow the same pattern. After the 8, 16 and 32-bit processors, the 64-Bit CPUs are now starting to take over the desktop.

AMD Athlon 64-FX
AMD Athlon 64-FX

While 64-bit processors have been commonplace for servers for years, CPUs for the desktop are now coming onto the market. The first of these was launched by AMD with its “Opteron” server processor, introduced in 2003, and its 64-bit technology was ported to the “Athlon” family desktop processors in the same year. In contrast to Intel’s 64-bit server flagship “Itanium,” AMD did not pursue the strategy of launching a purely 64-bit CPU, and instead offered an enhancement to the existing 32-bit processors, for the purely 64-bit processors have one distinct disadvantage: they can only process 64-bit code natively. An emulation mode, which severely affects performance, is needed to run existing 32-bit applications on the 64-bit processors.

Slow changeover

However, the processors enhanced with 64-bit instructions, which are often called x64, following on from x86, have three different modes of operating. In native 32-bit mode, they can use the existing operating systems and applications without adversely affecting performance. As a second mode, 32-bit applications can be used in an emulation on 64-bit operating systems. The third mode is the purely 64-bit mode with corresponding operating systems and applications. This architecture makes it possible to enter the world of 64-bit slowly and to migrate step by step.

Intel Sequence 6xx
Intel Sequence 6xx

Intel has now also recognized that this approach is better suited to establishing the new technology on the market. A few weeks ago, the market leader in desktop processors also launched CPUs with enhanced 64-bit capabilities as part of its “Pentium 4” family. These are marketed with the label “Sequence 6xx.”
With their desktop strategies, Intel and AMD are thus following market requirements, because the introduction of 64-bit desktop systems in enterprises will initially take some time. For example, there is currently still no operating system suitable for the mass market. While the open source community converted Linux to x64 CPUs at an early stage, a modified Microsoft Windows system is essential for widespread acceptance. Microsoft recently published the “Release Candidate 2” of Windows XP for 64-bit systems. The final version should be available in the coming months. In the case of the applications too, it will be some time before suitable software is available.

Apple G5
Apple G5

Apple, on the other hand, is some way ahead: in the new top models of the G5 series, the PowerPC processor “G5” from Apple and IBM is already working with 64 bits. The MacOS, which is also provided, has been modified accordingly, making Apple currently the only provider of 64-bit desktops with a standardized and end-to-end platform.

Unlimited memory – at least in theory

The great advantage of 64-bit systems is seen in memory-hungry applications such as CAD: while a 32-bit processor can address a working memory of no more than four gigabytes, the 64-bit systems have 16 exabytes at their disposal (1 EB = 1,152,921,504,606,846,976 bytes). However, at the moment, this value is only possible in theory, and we therefore talk of “virtual memory.” The 64-bit processors for desktops currently available on the market can only manage a few TBs of physical memory. The mainboards are another limiting factor – these usually have four slots for memory modules, each of which can take two GB. In practice, therefore, more than eight GB is not possible. However, even this modest value is twice the available working memory offered in the 32-bit environment.
Other advantages of the 64-bit machine, such as the ability to process several instructions per cycle, have hardly any effect on the systems available today, and subjective computer performance is equivalent to that of the top processors in the 32-bit environment. However, the new processors have a great deal to offer that is not directly connected with 64-bit capability but still brings clear benefits in day-to-day use.

Progress in all areas

Intel and AMD have taken an important step towards quieter, energy-saving computers by giving their 64-bit processors notebook technology. Both the “Athlon 64” and the “Pentium 4” from the 6xx sequence reduce the time cycle when full computing performance is not required. At AMD, this feature, known as “Cool & Quiet” has long been included in the notebook products, while Intel has marketed this technology for years with the name “Speed Step.” The lower energy required also reduces the fan performance needed – smaller fans controlled on a requirements basis make the PCs much quieter.
Another interesting feature of the x64 processors is “NX.” The abbreviation stands for “no execution” and addresses a fundamental problem of conventional x86 architectures. These enable executable programs and data to be merged, which means that code can be imported to a computer and executed without the user noticing. In the 64-bit devices, files such as this are loaded to a special storage area in which it is not possible to execute code. AMD markets this mechanism with the name “EVP” (enhanced virus protection), Intel as “XD” (execute disable). However, NX must also be supported by the operating system, which is the case on Windows XP with Service Pack 2.

Suitable hardware needed

However, it takes more than just the processors and a suitable operating system. Another key factor in determining the success of 64-bit desktops will be the point at which the software and hardware manufacturers jump on board. The providers of PC components, in particular, have a key position here: the old device drivers for Windows XP do not work on the 64-bit version of the operating system. For the advantages of the new platform to be fully exploited, modified drivers must be available, otherwise a changeover to the new operating system is not possible. However, hardware manufacturers will not offer the necessary drivers on a wide scale until the 64-bit desktops have achieved a certain degree of success in terms of use.
However, there is no doubt that the 64-bit desktop will enjoy long-term market success. As in the past, the “early adopters” will be gamers with a large hardware budget. As the products become more widespread and sophisticated, enterprises will also be able to benefit from their advantages. Even if it seems unimaginable today for the capabilities of the 64-bit PCs to ever be fully exploited, the killer application is just a question of time. Here too, a look back into the past reveals the opposition new IT developments have come up against: 20 years ago, it was inconceivable for an individual to be able to fill a 20 MB hard disk, while today, the same space is not even enough to hold a company’s marketing PowerPoint presentations. However, widespread market penetration cannot be expected for a couple of years. The Aberdeen Group estimates that the market will need the options offered by the 64-bit platform up until 2010.
The way seems to be clear for 64 bits. As market observers have paid little attention to this subject to date, only the IT providers can highlight current trends. “In the server market, the switch to 64-bit system is practically complete,” according to Sven Kretschmer, server product manager at component and notebook manufacturer Asus. “In mid 2004, 64 bits were a perk, but have since become standard. I expect to see a similar development for desktop PCs through the increasing spread of AMD Athlon 64 and Intel Pentium 4 from the 600 series.” This is confirmed by Alexander Spohr, purchasing manager at the European distributor Wave Computersysteme: “At Wave, the Athlon 64 CPUs are currently generating 50 percent of the total CPU sales.” He expects the innovation to win through in the coming year.
Because there are still some incalculable factors involved, users should follow the recommendations of Forrester Research when considering a change to the new technology – the advice was actually intended for the server segment, but also applies unreservedly for desktops. The market research company recommends a change-over in three steps: As a first step, the user should introduce the new hardware and run and evaluate the existing operating systems and software solutions on it. Step two according to Forrester is the replacement of the 32-bit operating system with a 64-bit version. Once suitable applications are available, there will then be nothing standing in the way of a switch to a purely 64-bit platform.

Jan Schulze
Jan Schulze