| SAN JOSE, Calif. — Intel Corp. formally rolls out server versions of its 45-nm Nehalem processors Monday (March 30). The Xeon 5500 chips integrate memory controllers and a high-speed interconnect, taking a page from archrival Advanced Micro Devices which pioneered the approach in x86 chips.
The Xeon 5500 sports four, dual-threaded cores; will come in speed ranges from 2.0 to 2.93 GHz and versions running at 60, 80 and 95W. To accommodate the new CPUs, top tier server makers including Dell, IBM and Hewlett-Packard have designed new motherboards aimed at lowering system power while expanding memory, networking and management capabilities.
Intel's initial chips support systems using two processors, giving them the equivalent of 16 threads per system. That matches AMD's current 45nm Shanghai chips that debuted in November, supporting in a single system up to four quad-core chips that are single threaded.
Later this year, Intel will roll Nehalem server chips supporting four-processor systems, giving it a significant edge over AMD in threads per system. AMD will counter late this year with a six-core processor dubbed Istanbul.
"The Nehalem chips leap ahead of AMD in almost all regards and turn what had been advantages for AMD into advantages for Intel," said Nathan Brookwood, principal of market watcher Insight64 (Saratoga, Calif.).
The CPU battle going forward will not be about architecture but "about how good is your memory controller and how fast is your processor link," he said. "It's not a crushing blow for AMD, but it's incumbent on them to keep executing as well as they have been in the last year."
The Xeon 5500 chips support three 64-bit DDR3 memory links, compared to two 64-bit DDR2 memory interfaces on AMD's server chips. That gives Intel significant bragging rights in memory bandwidth and latency, key features it has trailed in to date.
"AMD could demonstrate Shanghai could outperform previous Intel quad-core CPUs in some respects, especially when benchmarks were memory-intensive or required low latency," said Brookwood. "These are features Intel has now co-opted."
The Intel chips use a new Quick Path Interconnect replacing an aging front-side bus that had been considered a performance bottleneck. However QPI is generally seen as roughly equivalent to the HyperTransport interconnect AMD uses. | 
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