Xserve (2009)

available, as it will address up to 16TB of RAM.

Remote frustrations

Apple's Lights-Out Management (LOM) is on its third revision, and is still disappointing. The 2009 edition advertises itself via Bonjour, making it easier to discover and monitor Xserves with Server Monitor. However, the LOM still piggybacks on a service Ethernet connector, still lacks shell access to Mac OS X Server, and still lacks KVM-over-IP functionality. Given that Lights-Out Management enables privileged access on a secure network, it would be very convenient if an administrator could use the LOM to obtain shell access or control the Xserve via Screen Sharing. These features have been available on competing servers from HP, Sun, and Dell for years. Instead, these functions may only be accessed from within Mac OS X Server, on a service IP network.

With Apple's implementation, administrators must dedicate multiple IP addresses on different networks, and employ either VLAN or firewall trickery to secure the network ports used for administrative access. Were these ports accessible from the LOM on a secure administrative network, an administrator could just connect to the LOM and have full control in a secure manner. In today's marketplace, Apple's LOM is sadly incomplete.

Testing performance and power

Intel's Nehalem architecture provides a substantial increase in performance, despite a slower clock speed than previous models. Here's why: Turbo Boost allows the processor to disable idle cores while running a busy core at a higher-than-normal speed. Hyper-threading technology allows a core to execute two threads simultaneously; each core presents itself to the OS as two virtual cores, and thus Mac OS X Server treats an 8-core Xserve as though it has 16 cores. Taken together, these features enable single-threaded applications to run faster than expected, and multi-threaded applications can aggressively scale out to take advantage of parallel processing.

I tested the 2009 Xserve's performance against an available 2008-model Xserve. The 2008 model uses 2.8GHz Harpertown Xeon processors and lacks the SSD, but is otherwise identical. To test their relative performance, I constructed a Podcast Producer workflow with 15 concurrent encode tasks, then submitted multiple jobs using the same workflow; each server was thus oversubscribed beyond its processing capacity. Despite a 24 percent disadvantage in clock speed, the 2009 Xserve finished 44 percent faster. I measured both servers' power consumption at the plug: the 2009 Xserve uses 25 percent less power when idle, and 10 percent less at peak load. Likewise, the new model's exhaust air is 30 percent cooler at peak load; the new Xserve measured 90 degrees, compared to 115 degrees (Farenheit) on the previous Harpertown model. Performance per watt has been a marketing mantra for the last few years, but rarely have we seen such a dramatic increase in real-world performance, paired with a concurrent decline in power use and heat, as we do with the new Xserve.

Video card dilemma

The Xserve has always occupied two disparate worlds: video editing and the data center. This duality leads to suboptimal compromises for both audiences, as exemplified by the included Nvidia GeForce GT120 video card. While this card is the same as the one in a Mac Pro, its 256MB of video RAM is half that of its desktop counterpart. Apple says the GT120 card is sufficient to run their pro apps, such as Final Cut Pro or Aperture, and can drive two 30-inch displays, but video users may well wish for a high-performance GPU. (Apple doesn't offer an alternative graphics card option for the Xserve as it does for the Mac Pro.)

At the same time, the video card is over-engineered and overpriced for typical data center needs, where only simple 2-D video is necessary. Likewise, the Mini DisplayPort connector frustrates data center operators, as a dongle is necessary to attach to a KVM switch. (The Xserve uses the same Mini DisplayPort adapters as other Macs, in VGA and DVI varieties; unlike