After several months of previews and sneak peeks, Intel has now launched its Xeon Quad-Core 5500-series server CPUs based on Nehalem architecture and socket LGA 1366. Interestingly enough, the company claims that they are its most revolutionary server processors since addressing the market with the Intel Pentium Pro processor almost 15 years ago.

The Nehalem Efficient-Platform offers the same raw processing capability of the groundbreaking Core i7 processor family, with one slight change in the architecture. Rather than having a single QPI link from the CPU to the IOH, the Xeon 5500-series processors will have an additional QPI link for direct crosstalk between two CPUs. This allows almost all applications to run faster, as the CPUs can share Level 3 cache information and can access DDR3 memory information from one other. However, the pre-fetchers of a Core i7 processor are optimized for consumer applications rather than server processes, which means that a Nehalem CPU and a Nehalem-EP CPU clocked at the same speeds will still perform slightly differently.

According to Intel, the new enterprise-class chips can automatically adjust to specified energy usage levels, speed data center transactions and customer database queries. Like Core i7, the Xeon 5500-series supports Simultaneous Multi-Threading, formerly known as Hyper-Threading. This technology allows the spare resources of each execution unit to run a second parallel thread, resulting in a significant performance boost in a number of growing applications.

"The Intel Xeon processor 5500 series is the foundation for the next decade of innovation," said Patrick Gelsinger, senior vice president and general manager of Intel's Digital Enterprise Group. "These chips showcase groundbreaking advances in performance, virtualization and workload management, which will create opportunities to solve the world's most complex challenges and push the limits of science and technology."

Interestingly enough, the Xeon 5500-series processors with two QPI links will in fact work on some Intel Core i7/X58 platform motherboards. Yet it is important to keep in mind that these boards use standard, non-ECC unbuffered DDR3. A proper server motherboard for two or more of these chips requires ECC registered DDR3.