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power modes. Some servers, especially high-density blade servers being
deployed in environments with large scaling needs, use DC power directly,
without AC-to-DC conversion. DC power requires a different physical
power infrastructure than the normal AC power found in most data centers;
however, for some environments, DC power is worth keeping an eye on as
an emerging technology.
7.2.5 Measuring and Comparing Server Performance
Comparing server performance can be like trying to compare apples to
oranges. Significant differences can complicate comparing different operat-
ing systems, applications, and hardware platform configurations. Another
factor is what metrics are being used—percent of CPU processor utilization, ...