Hyper-Threading Technology, New Feature of Intel Xeon Processor White Paper
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On the down side, the existing single threaded applications do not experience the benefit of
Hyper-Threading technology. In fact, there can sometimes be disruption by the alternative thread,
such as the thread that uses a spin lock without pause instruction. Multi-threaded applications that
are optimized for MP systems also need to consider resource contention that destroys the
effectiveness of hand-tuned highly optimized code (games and streaming media applications).
Hyper-Threading technology can provide a performance gain of up to 30% when executing under
multi-threaded OS and applications with code that is tuned for Hyper-Threaded3 technology over
a comparable IA-32 processor without Hyper-Threading technology. For workstation applications
that are more multi-tasked and more memory intensive, there is more benefit to using two
physical processors as compared to using a single Hyper-Threading technology enabled
processor.
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Tuned instructions for Hyper-threaded is minimize the resource contention
