Pros: Ready to run. True headless booting. Unlimited licenses for Windows, Mac, and NFS file sharing clients. 12 1,066MHz DDR3 DIMM sockets leverage Nehalem's triple-channel on-chip RAM controller. Independent system management controller ('lights out management') with GUI, SNMP, and IPMI 2.0 support. Optional integrated hardware RAID controller with battery-backed RAM cache.
Cons: Lights-out management controller lacks KVM over IP support; no official serial over LAN support. Proprietary drive trays are not user-upgradeable with raw drives.
From the start, Apple's Xserve has ranked best-in-class in build quality, engineering, durability, and serviceability among 1U x86 rack servers. The newest Xserve, redesigned around Intel's Nehalem Xeon quad-core CPU, adds performance to the list of Xserve's leadership criteria. Nehalem Xserve is very likely the fastest, most energy-efficient, and most cost-effective dual-socket 1U rack server on the market.
Xserve's designers didn't need to commission a forward-looking study of enterprise server buyers to cook up Nehalem Xserve's specifications. It only had to chat with the IT leaders responsible for iTunes Music Store, iPhone App Store, MobileMe, Apple Store, and Apple Developer Connection. Apple's own requirements already reflect what analysts predict for the cloud. Ideal cloud servers will strike a balance between low power utilization and high reserve performance that's nearly impossible to achieve. By linking Intel's Nehalem architecture with custom system management hardware and a platform-tuned OS, Apple aimed for that server power/performance ideal and scored.
Nehalem Xserve is not everything it could be; I want to see lower power consumption at idle, for example. But those who buy this server will witness it evolve in firmware and software. Nehalem Xserve is a market-leading system now, and it'll be even better a year on.
The things that matter most to a massive enterprise with multiple datacenters are reflected in Xserve's feature list: A standards-based (IPMI 2.0) lights-out management controller is wired to an incomparably broad array of hardware sensors for local and remote monitoring of health and power utilization. By default, Xserve is optimized for headless (no monitor, keyboard, or mouse) deployment and operation. If you do need a close encounter with Xserve, most of it comes apart easily with only a Phillips head screwdriver, and its large, captive screws won't dive into your case for that familiar and frustrating game of hide and seek. Xserve weighs less than other 1U rack servers, even fully loaded, and yet it's undeniably sturdy. Xserve is a pleasure to work with at any distance.
It starts with Nehalem
Nehalem Xserve's marquee feature is, of course, the Intel Nehalem Xeon CPU and bus architecture. Intel pulled Xeon's formerly external memory controller onto the processor die, a shortcut that Apple claims more than doubles the effective memory throughput compared to the prior-generation Harpertown Xeon.
This claim is backed by STREAM benchmarks I've performed comparing the prior eight-core, 3GHz Xserve to the present 2.93GHz Nehalem model. The original eight-core Harpertown Xserve turned in a STREAM Triad score of 6,769MBps on a test with eight simultaneous threads, while the same binary running on Nehalem Xserve reports a Triad score of 19,065MBps.
That's no typo, and you should set aside your inclination to write off STREAM as a predictor of real-world server performance. In SPECjbb2005 (Java business benchmark) tests, the original eight-core Xserve scored 36,688 operations per second, while Nehalem Xserve managed a score of 83,926.