Intel launches Nehalem Xeon processors

The first Xeon chips based on Intel's Nehalem architecture

Intel has officially launched its first Nehalem-based Xeon chips for servers and workstations, bringing increased performance and greater power efficiency in the biggest overhaul of the Xeon platform for years.

The first wave of the new chips consists of the Xeon 5500 series for dual-socket systems, and the Xeon 3500 targeting single-socket systems, collectively known as Nehalem EP (Efficient Performance).

Nehalem processors for desktops were launched last year under the Core i7 brand, while the Nehalem EX for servers with four or more sockets is expected later this year.

Intel said that the increased performance of the new platform will enable firms to replace up to nine older servers with a single Nehalem-based system, making a strong case for purchasing new kit despite the current economic climate.

"We reckon customers can get a 9-to-1 consolidation ratio by replacing existing servers with Nehalem. There will be a capital expenditure hit to swallow, but after that there's a lot of justification for why customers should look at this now," said Intel's enterprise marketing manager Alan Priestley.

Gordon Haff, principal IT advisor at analyst firm Illuminata, said that it is easy for vendors to make impressive comparisons with older generations of kit, but gave a cautious welcome to the announcement.

"Nehalem is a very nice upgrade for Intel in the two-socket space. It has great performance, and great performance per watt. You can see this in the amount of activity the system vendors are planning around this launch," he said.

Dell announced Nehalem products last week as part of its new enterprise line-up, while Cisco's Unified Computing System is based on Nehalem servers. Lenovo unveiled new Nehalem workstations last week, while HP and Sun are also expected to introduce Nehalam systems shortly.

In addition to offering higher performance, Nehalem systems will consume up to 20 per cent less energy which, combined with the need for fewer servers, leads to reduced operating expenditure, Intel said.

"Customers should see payback on any refresh within eight months," said Priestley.

The Nehalem architecture is a radical break from earlier Xeon processors, with an on-chip memory controller supporting a bandwidth of up to 32Gbit/s and Intel's QuickPath Interconnect (QPI) in place of the traditional system bus.

Each Nehalem EP chip has two QPI links, one connecting to the system chipset and the other between the two processor sockets in a system. Each is capable of transferring 25Gbit/s.

This huge increase in bandwidth helps keep each of the four processor cores fed with data, Priestley said.

Systems based on Nehalem EP can support up to 144GB of DDR3 memory but, while the memory controller supports up to 1333MHz, Priestley warned that densely populated memory slots would be limited to the slower 1066MHz speed.

An updated version of Intel's Hyper-Threading technology enables each processor core to handle two simultaneous threads, so each quad-core chip can run eight threads simultaneously, delivering a total of 16 per two-socket system.

Another feature of Nehalem called Turbo Boost helps make maximum use of processor power. If the operating system requests more performance, and the chip is within its thermal power constraints, it can ramp up the clock speed for each individual core.

Meanwhile, Nehalem has more fine-grained control over power, and can almost completely shut off power to individual cores if they are not being used, according to Priestley.

Intel's new silicon also has extended virtualisation support, including faster transitions between host and guest modes, better support for I/O to virtual machines, and Intel's FlexMigration that enables live migration of virtual machines between servers based on Nehalem and existing Intel chips.

The Xeon 5500 series is available in clock speeds from 3.2GHz to 1.86GHz, with four power rating bands of 130W, 95W, 80W and up to 60W. The single-socket Xeon 3500 series is available at 3.2GHz, 2.93GHz and 2.66GHz in the 130W band only.