IT is rediscovering a simple but nearly forgotten principle: Throughput and capacity are everything. It hardly matters how fast the processor is if, like a Ferrari in city traffic, it bogs down every time it has to reach out to memory, peripherals, and other CPUs. A Xeon server running a static workload (that is, a predictable set of apps with stable resource requirements) is an unbeatable solution for the money. But today’s dynamic workloads -- from grid applications to real-time BI to virtualized resource partitioning -- force the 32-bit Xeon to spend as much time moving data as it does crunching data. It is optimized purely for the latter.
For dynamic workloads, IT has traditionally turned to 64-bit Unix servers with fast I/O and lots of expandability. Yet those servers’ enormous cost, trailing compute performance, and never-ending maintenance needs fueled the migration to Xeon in the first place. The ideal solution would be big-iron-like throughput and capacity without the sacrifice of Xeon-like compute performance and affordability -- something between cheap 32-bit PC servers and 64-bit IBM Power, Intel Itanium, or Sun Sparc machines. If low cost could be complemented by backward compatibility and smaller form factors, so much the better.
That sweet spot has been filled. Two emerging 64-bit platforms, one built on AMD’s Opteron and the other on IBM’s PowerPC 970FX, have stepped into the breach. Needless to say, we couldn’t wait to unpack two of the first systems based on these chips and see what
64-bit computing on a Xeon budget felt like. Our first test systems were a dual-Opteron reference server from AMD built on an MSI motherboard and a dual-processor Xserve G5 from Apple.
The value of the Opteron and PowerPC 970FX platforms reaches deeper than processor alone. Operating systems, buses, and chipsets all play significant roles. But CPU architecture remains the primary differentiator in this new class of 64-bit systems.
AMD’s Opteron is the server chip in a lineup of 64-bit, Pentium-compatible processors that includes the desktop, mobile Athlon 64, and the groundbreaking Athlon 64 FX-53 for high-performance workstations. Of these, only Opteron supports multiprocessor configurations. Opteron’s magic is its integration of north bridge functionality -- memory and CPU communication -- into the chip itself.
The Xserve G5’s PowerPC 970FX is the latest product of the partnership among Apple, IBM, and Motorola. IBM contributed the core of its Power4 64-bit enterprise CPU to the PowerPC 970FX. Apple handled the rest of the Xserve G5’s system design, including the buses, north bridge logic, south bridge logic, and system (health monitoring) controller.
Both systems were tested as configured by the vendors, except that we bumped up both machines to 4GB of RAM. Standard features in both servers included dual Gigabit Ethernet ports, removable hard drive trays, basic VGA cards, and USB ports. Both machines came with server management software and could monitor multiple servers. The Opteron server was capable of lights-out management -- that is, remote control of power, configuration, and diagnostics while the server’s power is turned off.
You can’t break up this act