• 
• 
• 
• 
• 

 1 of 5

Gallery

The 64-bit question

Posted on 10 Dec 2002 at 17:57

Dubbed 'glueless multiprocessing', this approach does away with the need for complex multiprocessing chipsets, making life easier for motherboard manufacturers. Also, it makes for better scalability, with the HyperTransport bus of the Hammer architecture providing greater bandwidth and lower latency than is possible using the shared bus of the Itanium. This should enable AMD to at least get a toehold in the SMP market, with plans to introduce four-way and eight-way servers where previously it was limited to just two-way with the Athlon chip.

But, just as importantly, AMD doesn't see 64-bit computing limited solely to high-end servers and workstations. Two implementations of Hammer are due to be released during 2003. Only one - the Opteron - is for multiprocessing servers and workstations, with three HyperTransport buses per processor to enable scaling up to eight-way.

The other is a 64-bit Athlon with just two such buses, which will be used in ordinary desktop and notebook PCs. The backwards compatibility of Hammer could really score here, giving AMD an edge over Intel, which is sticking with 32-bit processors in this market for the foreseeable future.

Infinity and beyond
'That's all very interesting,' you might say, 'but where are these new 64-bit processors taking us and when will we be able to get hold of them?' The answer to this depends on what type of system you're after.

If it's a server platform, you can get 64-bit solutions already. When it comes to Unix-based mid-range servers, the market is mature and you're almost spoilt for choice, although that's set to change. Compaq, for example, announced two years ago that it would be phasing out the 64-bit Alpha chip (inherited from Digital) in favour of Intel's Itanium. Post merger, the new HP will be continuing that programme and, likewise, replacing its own 64-bit PA-RISC chip with the Intel silicon.

The good news for existing customers is that this will be a gradual process. Itanium-based processing modules are being produced that can be plugged in without having to change other components. Nor will it be necessary for major software changes, especially on PA-RISC servers, as HP co-developed the Itanium and made sure native support for its instruction set was built in.

Elsewhere, Sun continues to plough its own hardware furrow, deploying its 64-bit UltraSPARC processor in servers and high-end workstations. And IBM is continuing to develop its 64-bit Power processor for use in servers running AIX, while at the same time also deploying the Itanium in its x-series line. Plans to port AIX to the Intel 64-bit chip have been shelved - IBM now favours Linux and Windows for this platform.

Lower down the scale, the leading vendors of industry-standard (Intel-based) servers have all announced products based on the Itanium 2, the first 'production' version of the IA-64 chip. All will be multiprocessing systems, although initial shipments will only be two-way and four-way, as the development of suitable chipsets has lagged behind the introduction of the processors. Shipping dates will also be affected by software availability (see 64-bit software), particularly .NET Server 2003, and it's likely to take another year or two for the market to start moving.

As for AMD, at the time of writing none of the big-name vendors had announced servers based on the Opteron processor, which is unlikely to ship in volume before mid-2003. There are lots of rumours, however, and the x86 compatibility features of the Opteron could well see a number of smaller vendors adopting the processor over the next few months. Unfortunately, the lack of software support means these will have to compete against 32-bit Xeon MP systems to begin with, as well as the Intel marketing muscle in this market.