Functional Architecture
Intel® Server Board S5500HV/Intel® Server System SR1670HV TPS
Revision 1.2
Intel Confidential
10
Intel order number E69391-006
3.1.1.2
Intel
®
QuickPath Interconnect (Intel
®
QPI)
Intel
®
QPI is a cache-coherent, link-based interconnect specification for processor, chipset, and
I/O bridge components. Intel
®
QPI can be used in a wide variety of desktop, mobile, and server
platforms spanning IA-32 and Intel
®
Itanium
®
architectures. Intel
®
QPI also provides support for
high-performance I/O transfer between I/O nodes. It allows connection to standard I/O buses
such as PCI Express*, PCI-X, PCI (including peer-to-peer communication support), AGP, etc.,
through appropriate bridges.
Each Intel
®
QPI link consists of 20 pairs of uni-directional differential lanes for the transmitter
and receiver, plus a differential forwarded clock. A full width Intel
®
QPI link pair consists of 84
signals (20 differential pairs in each direction) plus a forwarded differential clock in each
direction. Each Intel
®
Xeon
®
Processor 5500 Series and 5600 Series supports two Intel
®
QPI
links, one going to the other processor and the other to the Intel
®
5500 Chipset IOH.
In the current implementation, Intel
®
QPI ports are capable of operating at transfer rates of up to
6.4 GT/s. Intel
®
QPI ports operate at multiple lane widths (full - 20 lanes, half - 10 lanes, quarter
- 5 lanes) independently in each direction between a pair of devices communicating via Intel
®
QPI. The server board supports full width communication only.
3.1.1.3
Intel
®
Hyper-Threading Technology
Intel
®
Hyper-Threading Technology lets you run two threads at the same time per core. This
capability lets the processor take advantage of a 4-wide execution engine, effectively hiding the
latency of a single thread. However, the data residing in L1/L2
must
be present in 3rd level
cache.
This is the most power efficient performance feature of the Intel
®
Xeon
®
Processor 5500 Series
and 5600 Series. It’s very efficient performance boost that comes at a very low die area cost.
Depending on the application, it can provide significant performance benefit and is much more
efficient than adding an entire core. It supports larger caches and provides for massive memory
bandwidth.
3.1.1.4
Intel
®
Intelligent Power Technology
The Intel
®
Xeon
®
Processor 5500 Series and 5600 Series feature two Intel
®
Intelligent Power
Technologies:
Integrated Power Gates
- this feature lets individual idle cores reduce power to nearly zero
independently. Core power can be controlled automatically or manually.
Automated Low Power States
– this feature allows for more and lower CPU power states with
reduced latency during transitions. Also, it now features power management on memory and I/O
chip as well as the processor. This adjusts system power consumption based on real-time loads.
3.1.1.5
Turbo Mode
Intel
®
Turbo Boost Technology opportunistically and automatically allows the processor to run
faster than the marked frequency if the part is operating below power, temperature, and current
limits. This can result in increased performance of both multi-threaded and single threaded
workloads.
