Dual-core servers

Multi-core processors deliver many benefits, including much-improved performance per watt, over single-core designs. We examine three dual-core servers from the leading vendors to see what this technology can do for your business.

Multi-core processor technology is having a big impact in the datacentre, with dual-core servers, in particular, now commonplace. Organisations are reaping a number of significant benefits, performance foremost among them. As the name implies, you get two processors on each dual-core chip, effectively doubling the amount of processing the host server can cope with; there are four cores per chip on the latest quad-core silicon. Add in other recent technological advances such as bigger cache sizes, plus faster memory and bus speeds, and the latest multi-cores can provide truly staggering increases in computing power. This power can be used to full advantage for consolidation and virtualisation projects, as well as for high-performance clustering and grid computing applications.

Another bonus is SMP compatibility, which means there’s no need to change your operating system or application software. It's also possible to scale servers to suit a wide variety of needs and budgets: a 2-way dual-core server, for example, is the equivalent of a 4-way single-core system, and on a 4-way dual-core setup you get the benefit of eight cores at a 4-way price.

Socket compatibility should also make upgrading from dual-core to quad-core a simple matter of swapping chips. However, make sure you check before committing, as some recent changes in socket design mean that this isn’t always possible on early dual-core server implementations.

A less publicised, but equally important, benefit of multi-core technology is the reduced amount of electricity that processors need, with vendors vying to deliver the best performance-per-watt ratio. That, in turn means lower operating costs — not to mention helping to save the planet. These benefits are further amplified by simply being able to do more with less. For example, just by upgrading to dual-core you could halve your current number of servers, and still do the same amount of work — if not more.

Of course, it’s not always that simple, and there are many decisions to be made along the way. The key processor vendors have all developed multi-core processors, with companies like IBM and Sun leading the charge on their proprietary Unix and mainframe servers. In the industry-standard market, however, Intel and AMD are the main players and both offer 64-bit dual-core — and, more recently, quad-core — processors that can run either Windows or Linux software.

Interestingly, Intel hasn’t been calling all the shots, with AMD's Opteron family of dual-core processors stealing a march both in terms of technology and speed to market. However, Intel is fighting back and its latest dual-core Xeons are a huge improvement compared to earlier attempts. Intel has also beaten AMD to the quad-core punch, albeit with some reservations (see 'What next for multi-core' for details).

What we tested

In addition to new processors, a lot more has been happening in the server market in terms of storage, networking and manageability, making it very difficult to test and compare like for like. All the more so given that servers come in a range of shapes and sizes — from free-standing towers, through rack-mount devices to highly space-efficient blade servers.

The aim of this group test, therefore, is to not try and attempt a direct comparison, but to provide a snapshot of the breadth of the most popular industry-standard dual-core servers currently available. More specifically, we’ve gathered together three 2-way dual-core servers designed to be used by enterprises for general file sharing, as front-end Web servers and more specialised hosting duties.

We’ve chosen one specific model each from market leaders Dell, HP and IBM, although it’s worth pointing out that the configurations are far from unique and you’ll find similar products from all three vendors, and others too. All support both Intel and AMD processors and all offer a range of freestanding, rack-mount and blade implementations.

Bear that in mind, and hopefully this round-up will provide a good insight as to what’s currently available and will help you investigate further the benefits that dual core and, in due course, quad core can provide to your business.

What next for multi-core?

Dual-core 64-bit server processors capable of running industry-standard x86 software are now readily available from both Intel and AMD. Moreover, despite a number of false starts, the latest implementations are pretty well matched in terms of both performance and power consumption.

If you’re in the market for a 2-way server, therefore, the processors to look out for are those in Intel's Xeon 5000 family and the Opteron 2000 range from AMD. The leading hardware vendors all offer servers based on both processors, and the focus of attention (as far as further development is concerned) has now switched to quad-core, with Intel the first to market in this area.

No new servers have been announced yet, but Intel-based servers designed to take the latest dual-core processors can also be fitted with quad-core chips. However, in order to beat AMD to the punch, Intel has opted for a compromise approach, effectively packaging two dual-core processors together to create the new quad-core Xeon implementation.

This compromise limits the performance gains that are possible and when AMD launches later this year (2007) its new Opteron (codenamed Barcelona) will feature four processing cores on a single die, with all the benefits of its Direct Connect architecture. As a result, AMD is confident that the quad-core Opteron will outperform Intel’s first-generation quad-core Xeon by a substantial margin.

However, as ever, that’s set to change when Intel comes out with its own on-die quad-core design. At which point both companies will claim parity and start to focus on 8-core designs and beyond.