After many years of venerable service, IBM is retiring the xSeries server line. In fact, IBM is retiring the "Series" nomenclature altogether, rebranding its entire mainstream server line "System x."

Although some might construe this move as a simple marketing ploy, the reasons behind the new name seem to run deeper than that. With the new System x line, IBM is betting the farm on virtualisation.

Taking this tack, IBM has made some major changes and introduced new functionality in its IBM Director server management toolset. I had the opportunity to host an IBM System x3550 in the lab, and with only a few reservations, I liked what I saw during testing.

X marks the spot

At first glance, the x3550 resembles the current xSeries 366. It's a 1U, dual-CPU rack-mount server with the standard IBM idiosyncrasies, such as the tiny recessed power switch and rather odd Ethernet cable retention and release mechanism in the rear. Inside, however, it's a different beast altogether.

The x3550 leverages the new crop of Intel virtualisation-enhanced chips with VT extensions to bring dual-core dual-CPU performance into a small form factor. Armed with as much as 32GB of PC5300 667MHz RAM, two 3.5-inch SATA or SAS drives or four 2.5-inch SAS drives, integrated hardware RAID, dual Broadcom Gigabit Ethernet ports, two x8 64-bit PCI-E slots, and six USB 2.0 ports, the new x3550 cuts a sharp figure.

The CPU options are also extensive, from Intel Xeon EM64T 5110s at 1.6GHz, 4MB of L2 cache, a 1GHz FSB (front-side bus), and a 65-watt power draw, to the Xeon EM64T 5160 chips at 3.0GHz, 4MB of shared L2 cache, a 1.3GHz FSB, and an 85-watt power draw per CPU.

The x3550's new disk I/O subsystem offers a variety of choices as well. Using standard SATA drives, the x3550 can be run with hardware RAID 0 or 1, and it can support as much as 500GB of raw storage.

You can use either 3.5-inch or 2.5-inch SAS drives, providing 600GB or 293GB of raw storage, respectively. With as many as 2.5-inch SAS drives in place, the embedded IBM ServeRAID controller will support RAID5 and RAID10 configurations to bolster speed and redundancy of local storage.

All of these changes are aimed straight at the virtualisation market. IBM believes that a significant number of its customers are considering implementing virtualised data centres within the next year and has built the x3550 with that in mind.

Pleasant performance

I had several days to work with an x3550 armed with 4GB of DDR667 RAM, two 36GB 2.5-inch SAS drives, and dual 2.66GHz Intel Xeon 5150 CPUs with the 1.3GHz FSB.

Given that the driving force behind this new server was virtualisation, testing that was my first order of business. I installed a beta version of VMware ESX Server 3 on a RAID1 mirror across the two SAS drives. After building several VMs and migrating a few onto the x3550, I ran some VM-based tests between the x3550 and a Dell PowerEdge 2800 with dual single-core 3.6GHz EM64T Xeon CPUs. I booted cloned Fedora Core 5 systems on each server as the sole running VM with 512MB of RAM each and ran some simple Apache Web serving benchmarks against each VM.

The VM hosted on the x3550 platform easily bested the other, achieving roughly a 25 percent performance gain in requests per second. The single-core/dual-core divide between the systems was definitely a factor, but the x3550's FSB and much faster RAM also played a significant part, despite the slower clock speed.

Management moves

IBM has also been working to integrate virtualisation support with its Director management framework. Director is designed to be a whole-enterprise server management suite, providing hooks to manage every IBM server product from mainframes to blade servers. It will give you sorted, well-organised views of hardware and software components on Windows and Linux servers deployed far and wide. Agents running on the servers provide the necessary feedback to the Director server.

At the VM level, Director now enables similar views of VMs running on VMware GSX and ESX virtualisation platforms, as well as Microsoft Virtual Server. This means there's very little difference in managing VMs versus physical servers, as the IBM agents loaded in virtual servers can deliver nearly the same resource and performance views as on a physical server. Coupled with hardware failure detection and notifications at the physical level, Director can handle dynamic VM migrations to keep virtual servers that are running on failing hardware online.

Director also offers the ability to perform automated bare-metal virtualisation host-server builds, such as turning up a new VMware ESX server to handle increased load. Although it's possible to perform basic initial VM configuration from within Director, IBM punts to VMware's VirtualCenter management tools to handle the rest.

The System x3550 is IBM's take on the future of the data centre -- a future based on low- to midrange server virtualisation, and rife with advanced management and deployment tools, dynamic load-aware resource sharing, and, of course, IBM hardware. The new crop of System x servers looks to be a solid step in that direction.


The System x3550 marks a definitive step forward in IBM’s march toward commodity-server virtualisation, offering a system tuned to the needs of a virtual environment, coupled with high-level management tools integrated into its Director product. The server, not without its share of IBM design quirks, performed well in the lab, and is recommended.