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Table 2. Software details

Software

RHEL 7.3 x86_64

Linux Kernel

3.10.0-514.el7.x86_64

BIOS

1.2.11

Intel Caffe

1.0.4

Intel MLSL (for multi-node tests)

2017.1.016

Caffe Model

intel_optimized/multinode/resnet_50_256_nodes_8k_batch (with

batch size modified)

Performance tests were conducted on three generations of servers supporting different Intel CPU technology. The system configuration

of these test beds is shown in Table 1 and the software configuration is listed in Table 2. This space is new and rapidly evolving, with

frameworks being continuously updated and optimized. We expect performance to continue to improve, with subsequent releases, as

such the results are intended to provide insights and not be taken as absolute.

As shown in Table 2 we used the Intel Caffe optimized multi-node version for all tests. There are differences between Intel’s

implementation of the single-node and multi-node Caffe models, and using the multi-node model across all configurations allows for an

accurate comparison between single and multi-node scaling results. Unless otherwise stated all tests were run using the compressed

ILSVRC 2012 (Imagenet) database which contains 1,281,167 images. The dataset is loaded into /dev/shm before the start of the test.

For each data point a parameter sweep was performed across three parameters: batch size, prefetch size, and thread count. Batch size

is the number of training examples fed into the model at one time, prefetch is the number of batches (of batch size) buffered in memory,

and thread count is the number of threads used per node. The results shown used the best results from the parameter sweep for each

test case. The metric used for comparison is images per second, which is calculated by taking the total number of images the model

has seen (batch_size * iterations * nodes) divided by the total training time. Training time does not include Caffe startup time.

Single Node Performance

To determine what processors might be best suited for these workloads we tested a variety of SKUs including Intel Xeon E5-2697 v4

(Broadwell – BDW); Silver, Gold and Platinum Intel Xeon Scalable Processor Family CPUs (Skylake - SKL), as well as an Intel Xeon

Phi CPU (KNL). The single node results are plotted in Figure 1 with the line graph showing results relative to the performance of the

E5–2697 v4 BDW system.