IBM xSeries 336 Intel Xeon EM64T-based and Sun Microsystems Sun Fire V40z-Opteron-based x64-bit servers are excellent systems that perform well and allow IT managers to make efficient use of current applications while preparing a path to 64-bit processing. During testing of the xSeries 336 and SunFire V40z, testers found that users planning to migrate to either technology implementation should first determine industry and organizational requirements. The first Intel EM64T processors and chip sets are for two-way systems, and later in 2004 Intel will update its Xeon MP platform to move EM64T into the four- and eight-way market. EM64T, which is compatible with the AMD64 architecture, will streamline tasks for software developers creating operating systems (OSs) and applications that support both platforms. xSeries 336 is a good choice for processing of 32-bit front-end applications in server farms or as a cluster node in high-performance computing environments and is rated good for usability, performance, interoperability, and security, and excellent for capability, management, and scalability. Sun Fire V40z can have up to four Opteron processors in a compact form factor and provides powerful performance for 32-bit environments, but lacks drivers for hot-plug PCI. Sun Fire V40z is rated excellent for capability, manageability, and security, and good for usability, performance, interoperability, and scalability.