Processors and motherboard
At the heart of the Scorpion WH300 is a pair of Opteron 246 processors from AMD. The 246 processors are designed for dual-processor environments, which makes them perfect for workstation applications.
Like the rest of AMD's Opteron line, the 246 is manufactured on a 0.13-micron silicon-on-insulator fabrication process and has an integrated memory controller right on the chip. Opterons have 128KB of L1 cache split evenly between data and instruction caches, and 1MB of L2 cache. The chips support SSE2 instructions and, of course, AMD's 64-bit extensions.
A number of dual Opteron platforms have trickled onto the market since the processor was launched this spring, but few workstation boards have really tapped the Opteron's full potential. Fortunately, Appro made the right call with the Scorpion's motherboard, choosing Tyan's Thunder K8W.
The Thunder K8W is the only dual Opteron board I'm aware of that features an AGP slot and eight DIMM slots. The board can accommodate a whopping 16GB of registered PC2700 DDR SDRAM, and also supports ECC. The real kicker, however, is the fact that each of the board's CPU sockets has its own 128-bit dual-channel memory controller hooked up to four DIMM slots. Many low-end dual Opteron boards tend to hang all their DIMM slots off a single memory controller integrated into one CPU. With dual banks of dual-channel RAM, the K8W promises twice the memory bandwidth of the average Opteron workstation motherboard. However, you'll need an operating system aware of the Opteron's non-uniform memory access (NUMA) architecture to take full advantage of the extra bandwidth and lower access latencies provided by the system's multiple on-chip memory controllers. Currently, only a couple of versions Microsoft's Windows Server operating systems are NUMA-aware; the current Windows XP kernel is not.
Second only to its support for gobs of DDR memory is the Thunder K8W's PCI-X support. The board's AMD 8131 PCI-X tunnel supports two 64-bit 100/133MHz slots on one PCI-X bus, and a couple of 64-bit 100/66MHz slots on a second bus. The second PCI-X bus is also hooked up to a Broadcom BCM5703C Gigabit Ethernet controller.
In the workstation world, high-speed networking and storage subsystems demand far more bandwidth than a shared PCI bus can provide. With two independent PCI-X busses, the Scorpion can accommodate RAID, SCSI, and Gigabit Ethernet without having to worry about sharing a standard 32-bit, 33MHz PCI bus.
Since PCI-X slots aren't compatible with standard PCI gear, the Thunder K8W also has a single 32-bit, 33MHz PCI slot.