AMD Opteron: First 64-bit x86 platform launched 10 years ago today

AMD rather than Intel was responsible for bringing 64-bit computing to the PC platform

AMD introduced its first Opteron chip 10 years ago today, bringing the x86 processor architecture into the 64-bit world and stealing a march on rival Intel, which was instead pushing Itanium as the way forward.

The launch of the Opteron was a significant step for AMD, which until then had languished as an also-ran trailing behind Intel. Suddenly, the chipmaker had a world-beating processor that started getting attention from server vendors and enterprise buyers, and for a time turned it into a serious rival for Intel in the business market.

Before Opteron, it was clear that the 32-bit x86 architecture was beginning to run out of steam for server and workstation applications. While Intel and AMD had ratcheted up the clock speed of their respective chips to boost performance, workloads were starting to bump up against the restrictions of a 32-bit memory space.

There was no shortage of 64-bit architectures available at the time, including Sun's Sparc and IBM's Power 4, but these were typically used in costly high-end systems, and were not compatible with the Windows applications many enterprises were operating from PC-based servers.

Intel itself had already decided to back the Itanium or IA-64 architecture it co-developed with HP as its path to 64-bit, but this also required new applications to take advantage of its explicitly parallel approach to boosting performance. An x86 emulation mode was provided, but this performed poorly compared with existing systems.

Many industry observers have speculated about Intel's folly in continuing to back the Itanium architecture, even when it became apparent that it was simply not living up to its promise. It is possible that the firm felt it had already poured too much investment into developing the platform to change tack.

Instead, it fell to AMD to take the logical step and simply extend the x86 architecture to include 64-bit instructions, resulting in what the firm called AMD64.

At a stroke, AMD was offering businesses the chance to give a performance boost to existing applications, with a seamless upgrade path to 64-bit software when this became available.

"You just take existing applications from Xeon servers and put them on Opteron servers. Then you move to a 64-bit operating system, and then you move your applications across to it. It's a staged, safe upgrade path; enterprises don't want to do big-bang stuff," said Richard Baker, AMD's European marketing manager at the time.

AMD Opteron: First 64-bit x86 platform launched 10 years ago today

AMD rather than Intel was responsible for bringing 64-bit computing to the PC platform

But the Opteron did not just bring 64-bit capability to PC servers, it also introduced a major change in the internal architecture of the server itself that made it much easier to build a multi-socket system.

Until that point, multiple processor chips simply shared a bus connection with the rest of the system. This arrangement created a memory bandwidth bottleneck that effectively made PC servers with more than four sockets impractical without a specialist chipset.

AMD solved this problem by giving each Opteron chip its own directly connected pool of memory, and introduced a high-speed point-to-point interconnect called HyperTransport to link the chips to each other and the rest of the system in a switched fabric.

"By moving the memory controller onto the processor die, it runs at core frequency, and each processor added [to the system] adds another memory controller, so memory bandwidth scales with the number of processors," explained Mark Tellez, then AMD's server/workstation marketing manager.

Despite these innovations, the Opteron was slow to gather support at first, not helped by the fact that a version of Windows Server 2003 with full support for AMD64 was not available for another two years. However, it was eventually adopted by many big-name enterprise vendors, notably HP but also IBM, Sun Microsystems and Dell.

In fact, so successful was the AMD architecture that Intel eventually licensed AMD's 64-bit extensions for its own processors, ensuring software compatibility between the two chipmakers' products going forwards.

Intel also developed its own point-to-point interconnect technology along the lines of HyperTransport, called QuickPath Interconnect (QPI), but this only debuted in 2009, many years after the first Opteron shipped.

Since the Opteron's introduction, 64-bit has spread to most PC processor chips, starting with AMD's own Athlon brand of desktop processors. Only a few notable exceptions, such as some Intel Atom chips, are now 32-bit only.

While AMD has had much success with Opteron, managing to get many hosting firms and cloud service providers to fill entire datacentres with Opteron servers, it has struggled to keep up its momentum against Intel over the past decade.

With successive launches, Intel has closed the performance and feature gap, and AMD has seen its share of the server market dwindle and Opteron-based systems slowly sidelined in the product line-up of many of the enterprise vendors.

Nevertheless, the Opteron remains the end result of a remarkably innovative period in AMD's history, introducing many of the features that are now a standard part of industry standard servers.