Intel AT80615005760AB, BX80615E74830 User Manual

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Intel® Xeon® Processor E7 Family

Performance Brief: Model Number Characteristics and Impact to Performance

Intel® Xeon® Processor E7 Family
Performance and Model Numbers

Intel® Xeon® Processor E7-8800/4800/2800 Product Families Characteristics and Impact to Performance

EXECUTIVE SUMMARY

Just like many automobile manufacturers and other companies that have multiple
product lines within their product family, server processors have model numbers
to help distinguish the differences in features and delineate value. As your
business grows, so does demand for your products and / or services with
additional customers, users, and transactions that strain your current IT
infrastructure and back-end databases. The Intel® Xeon® brand helps customers

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select the appropriate product line and family stack as their demand justifies it

.

This paper focuses specifically on the Intel Xeon processor E7 family which is designed to be expandable and
scalable for larger deployments of business- or mission-critical workloads such as on-line transaction
processing, physical-to-virtual machine consolidation projects, business intelligence, customer relationship
management (CRM), and enterprise resource planning (ERP) / line-of-business applications that generate
revenue. The model numbers (see Figure 1) help differentiate the capabilities of the processors and in the
case of the Intel Xeon processor E7 product family, the wayness or maximum number of processors (CPUs or
sockets) in a node can be two, four, or eight (contrasted to the Intel Xeon processor E3 or E5 families, which
support only one or two/four processors, respectively). Performance may scale as the number of processors
installed (wayness) in a server is increased (up to 94% efficiency as published in this paper); but in a two-way
server, regardless of the actual processor wayness capability, the throughput application performance would
be expected to be the same.

MODEL NUMBERS AND
SCALABILITY

For the Intel Xeon processor E7 family,
processor models (also called SKUs) are
available in three wayness
configurations – two, four, or eight

Figure 1 - 2012 Processor Numbering Example

sockets together). Within a given Intel Xeon processor E7-xxxx SKU, the difference in wayness is irrelevant if
populated in only a two-socket node and corresponding performance differences are negligible. For example,
the top-bin Intel Xeon processor E7-8870/E7-4870/E7-2870 all have the same socket type (8) and the same

socket native support (no third party

node controller required to connect the

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Intel® Xeon® Processor E7 Family Performance

processor SKU (70); which indicates same core frequency of 2.4 GHz, the same Intel® QuickPath Interconnect
speed of 6.4 GT/s, the same last-level cache (LLC) of 30 MB, and the same number of cores at 10 per
processor.

So the only difference is in the first product family number represents wayness (2, 4, or 8) capability indicating
that the Intel Xeon processor E7-4xxx and E7-8xxx models can scale natively beyond just 2-sockets (see
Figure 2 below). It is common IT practice to buy “headroom” by purchasing a larger server but only initially
partitioning a portion of the processor sockets for today’s level of requirements allowing for future compute
power expansion as the number of users, transactions, or problem fidelity increases. Ideally, with perfect
scaling, you can double the number of users, for example, when doubling the number of processor compute
power (assuming storage, memory, and I/O are scaled as to not be the bottleneck). However, when any of
these otherwise identical processors are populated in 2-sockets only though, performance throughput should
be expected to be the same.

Figure 2 - Intel® Xeon® Processor E7-8800/4800/2800 Product Family Numbering2

PERFORMANCE IMPACT

For the purposes of demonstrating the impact of model numbers on performance, the top of the advanced
capability levels of each product family is compared below (Intel Xeon processor E7-8870/4870/2870). Figure 3
below illustrates the options original equipment manufacturers (OEMs) have in designing an Intel Xeon processor
E7 family-based server.

Looking at the first number in
the Intel Xeon processor E7
family, -8xxx, -4xxx or -2xxx,
which represents the number
of processors natively
supported in a server, the
processors can scale to
support the increased number
of users, transactions or
throughput as additional
sockets are tested in
performance benchmarks.
The typical example of this

Figure 3 - Intel Xeon processor E7 family scalability to support 2- to 256-sockets3

benchmark that is fairly representative of typical integer-based, compute-intensive server applications to test the

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can be found while using the
SPECint*_rate_base2006

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2-socket

4-socket

8-socket

Intel® Xeon® Processor E7 Family Performance

number of users (typically matches the number of logical threads seen by the Operating System, OS)
simultaneously running a problem on a given server. The performance scaling is calculated by dividing the
resulting score from the maximum number of processors populated in one server by the score of the server with
n-way processors populated in another server configuration. So from 2- to 4- to 8-socket-based servers, the
perfect scaling would be four times, meaning that the number of users supported (or problems solved) in the 8­socket server is four times more than what a 2-socket server could support. The efficiency is measured by how
close a scale-up server performs comparatively to that perfect scaling, which in this case is quite reasonable at up
to 94% efficiency (see Figure 4 below).

Servers

Servers

Servers

Figure 4 - Scaling of supported users on multi-processor servers4

The Intel Xeon processor E7-8870 can be populated in a 2-, 4-, or 8-socket server configuration. This is due to the
Intel® QuickPath Interconnect (Intel® QPI) that allows the processors to share resources by allowing all of the
components to access other components through the mainboard network. Similar to the Intel Xeon processor E7­8870, the E7-4870 model supports 2- or 4-socket server configurations; but on the Intel Xeon processor E7-2870,
only 2-sockets can be populated in a server node (though multiple nodes can be joined together to form a larger
single server image ≥2S – see Figure 3 above).

There are no characteristics in each of the three processors noted above that differ, other than the wayness
capability. All three processors operate in the same number of available cores per socket, core frequency, Intel®
QPI speed, and cache structure (see Figure 2 above). Therefore, in a 2-socket server configuration, the
performance delta between the three will only be typical run-to-run variation due to a number of factors including
manufacturing variances that may affect the length of time the processors run above their marked frequency
using Intel® TurboBoost Technology. SPEC* allows for up to 1.75% variation. This hypothesis was confirmed
through testing using Intel internal labs and as seen in Figure 5 below as there is less than 0.5% difference in
performance between the three processors when in the same two-socket server configuration (see Table 1 below
for complete list of equivalent processor SKUs).

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