Product Reviews

It isn't often we see IBM beating the competition to the punch in the server market, but the latest xSeries 366 does just that and more. Aimed at ERP, email, database and e-commerce applications, this 3U rack server delivers a hardware specification and feature set that put it way ahead of its main rivals.

For starters, despite being 1U smaller than HP's ProLiant DL580, it can handle up to four Xeon MP processors and delivers full support for the next generation of Intel's dual-core Xeons. The 366 is built around IBM's X3 architecture, which it announced earlier this year after a three-year $100 million investment programme and is implemented as its XA-64e, or Hurricane, chipset. This delivers some impressive features, such as memory mirroring capabilities and support for the new Active PCI-X 2 standard. Another key feature is IBM's XceL4v dynamic server cache, which provides one main function in the 366. Embedded DRAM is used to provide a snoop filter look-up table, which aims to reduce traffic on the FSB (front side bus), as it minimises cache misses by storing a directory of processor cache lines.

The icing on this particular cake comes in the storage department. The 366 is the first server we've seen that delivers fully integrated Serial Attached SCSI (SAS) support. There's much more, as a closer look at the server's front panel shows it also uses the latest low-profile 2.5in SAS hard disks. When we brought you a first look at SAS in our exclusive review of the LSI Logic SAS3442X controller, we said this was going to be one of the most exciting storage developments yet. Its effect on the future development of SCSI technology will be significant, as will its impact on the server and storage markets. The use of 2.5in SAS hard disks has given the 366 a number of advantages, not least in stature, as the six hot-swap disk bays don't even take up a quarter of the front panel. The system was supplied with six 73.4GB SAS drives, so raw storage capacity doesn't take a hit either.

Tucking the hard disks up in the top corner has given IBM more leeway in internal design, as the storage

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arrangement doesn't have the same impact on airflow as conventional 3.5in hard disks. With over two-thirds of the front panel unimpeded, air is allowed to flow virtually unrestricted through the chassis. IBM has also squeezed in a small pop-out display pad, which provides direct access to its unique light-path diagnostics. This has been a staple feature of IBM servers for years now, and in the event of virtually any component failure a quick glance at this matrix of 18 LEDs will reveal the culprit.

Behind the front grille is the motherboard with four Xeon MP processor sockets. The review system came supplied with a pair of 3.6GHz CPUs. Installation of extra processors requires all fans and memory modules to be removed first, after which the entire board can be pulled out through the front panel. System memory is implemented with four separate cards, each with a quartet of DIMM sockets. The minimum requirement is for only one card to be populated, but adding more memory on the others brings mirroring into play. Memory in cards 1 and 2 is mirrored to that installed in cards 3 and 4 respectively, and as the two groups use different power buses a failed card can be hot-swapped out.

For basic storage, the server uses an Adaptec dual-channel SAS chipset, but the review system included IBM's optional ServeRAID-8i controller card, which is based on an Adaptec ASR-4005SAS card. This must be installed in a dedicated slot, where it takes over the SAS channels to deliver support for the standard range of RAID arrays plus RAID6. The latter requires a minimum of four drives, as it uses the capacity of two for redundancy and can survive the loss of two drives.

Expansion options are unaffected, as you're still left with six 266MHz PCI-X hot-plug slots to play with. There's more fault tolerance, as the pair of Broadcom Gigabit Ethernet ports can be joined together in a failover team and the system was also supplied with both 1,300W hot-swap power supplies. These can be lifted vertically from the chassis, so no rear clearance is required when replacing a failed unit. Cooling gets plenty of attention, with PCI slot section looked after by a bank of four hot-swap fans, while four more are positioned in front of the memory modules.

The xSeries 366 really has set the bar for the next generation of multiprocessor rack-mount servers. It's clearly capable of delivering a high processing density, which will get even greater when Intel releases its dual-core Xeons at the end of 2005. Expansion potential and fault tolerance are excellent, it's equipped with the latest RAID-protected SAS storage and backs it all up with excellent remote management and monitoring features.