Several years ago I drafted a white paper I called "x86 Everywhere". I started it in the fall of 2004, let it sit, and updated it in April 2005. It remains unfinished, but with the release today of Intel's Nehalem processor, I took a look at it again. Here is Part 2:
Three trends could allow what I call "x86 Everywhere" to happen.
The first trend is the decrease in value of large, partitionable, RISC/UNIX systems.
All major commercial RISC/UNIX systems vendors offer large systems that can support large workloads, or can be partitioned to support many medium-sized workloads. The primary reasons for deploying a medium-sized workload in a partition on a large server are expected growth beyond the capacity of typical midrange servers, higher system resource utilization, system management efficiencies of server consolidation, and customer politics and preferences. Each of these reasons is coming under assault by the advancement of Moore's law, and as a result, the value proposition of large, partitionable datacenter servers is declining.
The performance improvements brought about by Moore's law over the last several years have outpaced customer workload growth, allowing midrange systems to handle the expected growth of most customer workloads. In addition, the price of midrange RISC/UNIX system has declined significantly over the last several years, starting with Sun's UltraSPARC III based V880, whose price point was then met by IBM with the POWER4-based p650, and HP's strategy of offering standard configurations of PA-RISC and Itanium midrange systems at very aggressive prices. Moore's law has caused system utilization to drop, as processors are now very powerful.
Traditional physical based partitioning, such as Sun's Dynamic System Domains and HP's Node Partitions (nPars) do not provide adequate granularity given the performance of today's processors. The result is the rise of software-based partitioning, logical partitioning, and virtual machine technology, which are portable to smaller, less expensive RISC/UNIX systems. In the case of purely software based partitioning technology, it is portable to other ISAs such as x86 platforms. For example, virtual machine technology is primarily being used on x86 systems via VMware's products. These shift in server partitioning technology are also decreasing the value proposition of large and midrange RISC/UNIX servers.
The recent emphasis in the industry for provisioning and system management solutions, along with policy-based computing solutions to manage large numbers of discreet servers has yet to significantly change the industry, however improvements in this area have improved the system management efficiencies of distributed servers. This, along with some of the inherent provisioning and management efficiencies of software-based partitioning technologies (shared network and disk resources) have resulted in a decrease in the relative value of large partitionable systems.
One should note, this decrease in value is real. It is not simply a customer perception. First, physical partitioning is simply too expensive a method to achieve partitioning in a server. Markets define prices, not vendors. Costs define margins, not prices. In a scenario with two otherwise equivalent servers, one using physical partitioning, the other using logical partitioning, the logical partitionable server will offer the vendor greater margins. Similarly, designing a server with physical partitioning which offers the same granularity as logical partitioning would likely be abandoned for having too high a cost. Second, customers really are moving workloads from previous generation large servers to smaller servers of the current generation, rather than partitions on larger current generation servers. In 1998 a Sun customer might consider paying the 50% price premium of an E10K over multiple E4500s. The value the 50% premium represented, primarily in growth capacity, justified the premium. Today the premium an E20K has over multiple V890s or V490s is so much higher (around 150% more), few customers can justify the value the E20K price premium provides.
The effect of this is a leveling of playing field between RISC/UNIX servers and x86 servers. Midrange RISC/UNIX servers are becoming simpler and cheaper. Midrange x86 servers have become more robust. RISC ISAs versus the x86 ISA is become a "Coke versus Pepsi" decision: a flavor choice.
x86 Rises, Part 1: The Background