Specifications

14
Technology Overview
Xserve
Intelligent Power Capability
Intel Intelligent Power Capability comprises a set of capabilities designed to reduce
power consumption and design requirements. This feature manages the runtime
power consumption of all the processor’s execution cores. Advanced power gating
allows for an ultra-fine-grained logic control that turns on individual processor logic
subsystems only when they are needed. Also, many buses and arrays are split so
that data required in some modes of operation can be put in a low power state
when not needed.
Advanced Smart Cache
The Intel Advanced Smart Cache is a multicore-optimized cache. It improves
performance and efficiency by increasing the probability that each execution core
of a dual-core processor can access data from a higher-performance, more efficient
cache subsystem. To accomplish this, the dual-core Xeon processor shares 4MB of
L2 cache between cores. Unlike most multicore implementations, which leave each
execution core to store data in its own L2 cache, Advanced Smart Cache optimizes
cache resources by storing data in a single place that each core can access. By
sharing L2 caches among multiple cores, the Intel Advanced Smart Cache also allows
each core to dynamically utilize up to 100 percent of available L2 cache. When one
core has minimal cache requirements, other cores can increase their percentage of
L2 cache, reducing cache misses and increasing performance.
Smart Memory Access
Intel Smart Memory Access improves system performance by optimizing the use of
data bandwidth from the memory and cache subsystem and hiding the latency of
memory accesses. Most modern processors have prefetch engines that attempt to
predict data needs and load the needed data from main memory into processor cache
for faster retrieval. To do so, the processors must first resolve pending stores to main
memory for in-flight instructions to prevent any data violations that could result in
incorrect data being loaded or stored.
Intel Smart Memory Access provides a new capability called memory disambiguation.
Utilizing advanced algorithms to evaluate whether a load can be executed ahead of
a preceding store, this feature lets the processor spend less time waiting for memory
and more time processing, resulting in faster execution and more efficient use of
processor resources.
In addition, the Intel Core microarchitecture provides enhanced prefetch engines—
two per L1 cache and two per L2 cache—that detect streaming and striding data
patterns simultaneously. Smart Memory Access, using advanced prefetchers and
advanced memory disambiguation, results in improved execution throughput by
taking full advantage of available system bus bandwidth while hiding latency to the
main memory subsystem.
Advanced Digital Media Boost
SIMD processing accelerates data manipulation by simultaneously applying a single
instruction to multiple pieces of data. Whereas the PowerPC G5 processor uses the
Velocity Engine to achieve this function, the dual-core Xeon processor incorporates
an enhanced 128-bit Streaming SIMD Extensions (SSE) vector engine. Dual-Core Intel
Xeon processors include 13 new SSE instructions in SSE3 under the name Advanced
Digital Media Boost. On many previous-generation processors, 128-bit SSE, SSE2, and
SSE3 instructions were executed at a sustained rate of one complete instruction every
two clock cycles—for example, the lower 64 bits in one cycle and the upper 64 bits in
the next. The Dual-Core Intel Xeon processor enables these 128-bit instructions to be
completely executed at a throughput rate of one per clock cycle, effectively doubling
Increased energy efficiency
After labor, electricity and cooling
create the highest costs for data centers.
The 65-nanometer technology used in
manufacturing Dual-Core Intel Xeon
processors incorporates strained silicon
to improve transistor performance and
decrease power consumption. Less
energy consumed means less heat
dissipated—for increases in reliability
and decreases in cooling system costs.