The Dell EMC PowerEdge R7525 server provides exceptional MLPerf Inference v0.7 Results, which indicate that:

• Dell Technologies holds the #1 spot in performance per GPU with the NVIDIA A100-PCIe GPU on the DLRM-99 Server scenario
• Dell Technologies holds the #1 spot in performance per GPU with the NVIDIA A100-PCIe on the DLRM-99.9 Server scenario
• Dell Technologies holds the #1 spot in performance per GPU with the NVIDIA A100-PCIe on the ResNet-50 Server scenario

Summary

In this blog, we provide the performance numbers of our recently released Dell EMC PowerEdge R7525 server with two NVIDIA A100 GPUs on all the results of the MLPerf Inference v0.7 benchmark. Our results indicate that the PowerEdge R7525 server is an excellent choice for inference workloads. It delivers optimal performance for different tasks that are in the MLPerf Inference v0.7 benchmark. These tasks include image classification, object detection, medical image segmentation, speech to text, language processing, and recommendation. 

The PowerEdge R7525 server is a two-socket, 2U rack server that is designed to run workloads using flexible I/O and network configurations. The PowerEdge R7525 server features the 2nd Gen AMD EPYC processor, supports up to 32 DIMMs, has PCI Express (PCIe) Gen 4.0-enabled expansion slots, and provides a choice of network interface technologies to cover networking options. 

The following figure shows the front view of the PowerEdge R7525 server:

Figure 1. Dell EMC PowerEdge R7525 server

The PowerEdge R7525 server is designed to handle demanding workloads and for AI applications such as AI training for different kinds of models and inference for different deployment scenarios. The PowerEdge R7525 server supports various accelerators such as NVIDIA T4, NVIDIA V100S, NVIDIA RTX, and NVIDIA A100 GPU s. The following sections compare the performance of NVIDIA A100 GPUs with NVIDIA T4 and NVIDIA RTX GPUs using MLPerf Inference v0.7 as a benchmark.

The following table provides details of the PowerEdge R7525 server configuration and software environment for MLPerf Inference v0.7:

For more information about how to run the benchmark, see Running the MLPerf Inference v0.7 Benchmark on Dell EMC Systems.

MLPerf Inference v0.7 performance results

The MLPerf inference benchmark measures how fast a system can perform machine learning (ML) inference using a trained model in various deployment scenarios. The following results represent the Offline and Server scenarios of the MLPerf Inference benchmark. For more information about different scenarios, models, datasets, accuracy targets, and latency constraints in MLPerf Inference v0.7, see Deep Learning Performance with MLPerf Inference v0.7 Benchmark.

In the MLPerf inference evaluation framework, the LoadGen load generator sends inference queries to the system under test, in our case, the PowerEdge R7525 server with various GPU configurations. The system under test uses a backend (for example, TensorRT, TensorFlow, or PyTorch) to perform inferencing and sends the results back to LoadGen.

MLPerf has identified four different scenarios that enable representative testing of a wide variety of inference platforms and use cases. In this blog, we discuss the Offline and Server scenario performance. The main differences between these scenarios are based on how the queries are sent and received:

• Offline—One query with all samples is sent to the system under test. The system under test can send the results back once or multiple times in any order. The performance metric is samples per second.
• Server—Queries are sent to the system under test following a Poisson distribution (to model real-world random events). One query has one sample. The performance metric is queries per second (QPS) within latency bound.

Note:  Both the performance metrics for Offline and Server scenario represent the throughput of the system. 

In all the benchmarks, two NVIDIA A100 GPUs outperform eight NVIDIA T4 GPUs and three NVIDIA RTX800 GPUs for the following models:

• ResNet-50 image classification model
• SSD-ResNet34 object detection model
• RNN-T speech recognition model
• BERT language processing model
• DLRM recommender model
• 3D U-Net medical image segmentation model

The following graphs show PowerEdge R7525 server performance with two NVIDIA A100 GPUs, eight NVIDIA T4 GPUs, and three NVIDIA RTX8000 GPUs with 99% accuracy target benchmarks and 99.9% accuracy targets for applicable benchmarks:

• 99% accuracy (default accuracy) target benchmarks: ResNet-50, SSD-Resnet34, and RNN-T
• 99% and 99.9% accuracy (high accuracy) target benchmarks: DLRM, BERT, and 3D-Unet

99% accuracy target benchmarks

ResNet-50

The following figure shows results for the ResNet-50 model:

Figure 2. ResNet-50 Offline and Server inference performance

From the graph, we can derive the per GPU values. We divide the system throughput (containing all the GPUs) by the number of GPUs to get the Per GPU results as they are linearly scaled. 

SSD-Resnet34

The following figure shows the results for the SSD-Resnet34 model:

Figure 3. SSD-Resnet34 Offline and Server inference performance

RNN-T

The following figure shows the results for the RNN-T model:

Figure 4. RNN-T Offline and Server inference performance

99.9% accuracy target benchmarks

DLRM

The following figures show the results for the DLRM model with 99% and 99.9% accuracy:

Figure 5. DLRM Offline and Server Scenario inference performance – 99% and 99.9% accuracy                                   

 For the DLRM recommender and 3D U-Net medical image segmentation (see Figure 7) models, both 99% and 99.9% accuracy have the same throughput. The 99.9% accuracy benchmark also satisfies the required accuracy constraints with the same throughput as that of 99%.

BERT

The following figures show the results for the BERT model with 99%  and 99.9% accuracy:

Figure 6. BERT Offline and Server inference performance – 99% and 99.9% accuracy 

For the BERT language processing model, two NVIDIA A100 GPUs outperform eight NVIDIA T4 GPUs and three NVIDIA RTX8000 GPUs. However, the performance of three NVIDIA RTX8000 GPUs is a little better than that of eight NVIDIA T4 GPUs.

3D U-Net

For the 3D-Unet medical image segmentation model, only the Offline scenario benchmark is available.

The following figure shows the results for the 3D U-Net model Offline scenario:

Figure 7. 3D U-Net Offline inference performance 

For the 3D-Unet medical image segmentation model, since there is only offline scenario benchmark for 3D-Unet the above graph represents only Offline scenario.

The following table compares the throughput between two NVIDIA A100 GPUs, eight NVIDIA T4 GPUs, and three NVIDIA RTX8000 GPUs with 99% accuracy target benchmarks and 99.9% accuracy targets:

Conclusion

With support of NVIDIA A100, NVIDIA T4, or NVIDIA RTX8000 GPUs, Dell EMC PowerEdge R7525 server is an exceptional choice for various workloads that involve deep learning inference. However, the higher throughput that we observed with NVIDIA A100 GPUs translates to performance gains and faster business value for inference applications. 

Dell EMC PowerEdge R7525 server with two NVIDIA A100 GPUs delivers optimal performance for various inference workloads, whether it is in a batch inference setting such as Offline scenario or Online inference setting such as Server scenario. 

Next steps

In future blogs, we will discuss sizing the system (server and GPU configurations) correctly based on the type of workload (area and task).

Introduction 

Graphics Processing Units (GPUs) provide exceptional acceleration to power modern Artificial Intelligence (AI) and Deep Learning (DL) workloads. GPU resource allocation and isolation are some of the key components that data scientists working in a shared environment use to run their DL experiments effectively. The need for this allocation and isolation becomes apparent when a single user uses only a small percentage of the GPU, resulting in underutilized resources. Due to the complexity of the design and architecture, maximizing the use of GPU resources in shared environments has been a challenge. The introduction of Multi-Instance GPU (MIG) capabilities in the NVIDIA Ampere GPU architecture provides a way to partition NVIDIA A100 GPUs and allow complete isolation between GPU instances. The Dell Validated Design showcases the benefits of virtualization for AI workloads and MIG performance analysis. This design uses the most recent version of VMware vSphere along with the NVIDIA AI Enterprise suite on Dell PowerEdge servers and VxRail Hyperconverged Infrastructure (HCI). Also, the architecture incorporates Dell PowerScale storage that supplies the required analytical performance and parallelism at scale to feed the most data-hungry AI algorithms reliably.

In this blog, we examine some key concepts, setup, and MLPerf Inference v1.1 performance characterization for VMs hosted on Dell PowerEdge R750xa servers configured with MIG profiles on NVIDIA A100 80 GB GPUs. We compare the inference results for the ResNet50 and Bidirectional Encoder Representations from Transformers (BERT) models.

Key Concepts

Key concepts include:

• Multi-Instance GPU (MIG)—MIG capability is an innovative technology released with the NVIDIA A100 GPU that enables partitioning of the A100 GPU up to seven instances or independent MIG devices. Each MIG device operates in parallel and is equipped with its own memory, cache, and streaming multiprocessors.

In the following figure, each block shows a possible MIG device configuration in a single A100 80 GB GPU:

  Figure 1- MIG device configuration - A100 80 GB GPU

The figure illustrates the physical location of GPU instances after they have been instantiated on the GPU. Because GPU instances are generated and destroyed at various locations, fragmentation might occur. The physical location of one GPU instance influences whether more GPU instances can be formed next to it.

Supported profiles for the A100 80GB GPU include:

• 1g.10gb 
• 2g.20gb 
• 3g.40gb
• 4g.40gb
• 7g.80gb 

In Figure 1, a valid combination is constructed by beginning with an instance profile on the left and progressing to the right, ensuring that no two profiles overlap vertically. For detailed information about NVIDIA MIG profiles, see the NVIDIA Multi-Instance GPU User Guide.

• MLPERF—MLCommons™ is a consortium of leading researchers in AI from academia, research labs, and industry. Its mission is to "develop fair and useful benchmarks" that provide unbiased evaluations of training and inference performance for hardware, software, and services—all under controlled conditions. The foundation for  MLCommons began with the MLPerf benchmark in 2018, which rapidly scaled as a set of industry metrics to measure machine learning performance and promote transparency of machine learning techniques. To stay current with industry trends, MLPerf is always evolving, conducting new tests, and adding new workloads that represent the state of the art in AI. 

Setup for MLPerf Inference

A system under test consists of an ESXi host that can be operated from vSphere.

System details

The following table provides the system details.

Table 1: System details

System configuration for MLPerf Inference

The configuration for MLPerf Inference on a virtualized environment requires the following steps:

1. Boot the host with ESXi (see Installing ESXi on the management hosts), install the NVIDIA bootbank driver, enable MIG, and restart the host.
2. Create a virtual machine (VM) on the ESXi host with EFI boot mode (see Using GPUs with Virtual Machines on vSphere – Part 2: VMDirectPath I/O) and add the following advanced configuration settings:
   
   

   pciPassthru.use64bitMMIO: TRUE
   pciPassthru.allowP2P: TRUE
   pciPassthru.64bitMMIOSizeGB: 64

3. Change the VM settings and add a new PCIe device with a MIG profile (see Using GPUs with Virtual Machines on vSphere – Part 3: Installing the NVIDIA Virtual GPU Technology).
4. Boot the Linux-based operating system and run the following steps in the VM.
5. Install Docker, CMake (see Installing CMake), the build-essentials package, and CURL
6. Download and install the NVIDIA MIG driver (grid driver).
7. Install the nvidia-docker repository (see NVIDIA Container Toolkit Installation Guide) for running nvidia-containers.
8. Configure the nvidia-grid service to use the vGPU setting on the VM (see Using GPUs with Virtual Machines on vSphere – Part 3: Installing the NVIDIA Virtual GPU Technology) and update the licenses.
9. Run the following command to verify that the setup is successful:

nvidia-smi

Note: Each VM consists of 32 vCPUs and 64 GB memory.

MLPerf Inference configuration for MIG

When the system has been configured, configure MLPerf v1.1 on the MIG VMs. To run the MLPerf Inference benchmarks on a MIG-enabled system under test, do the following:

1. Add MIG details in the inference configuration file:
   Figure 2- Example configuration for running inferences using MIG enabled VMs
   
   
2. Add valid MIG specifications to the system variable in the system_list.py file.

Figure 3- Example system entry with MIG profiles

These steps complete the system setup, which is followed by building the image, generating engines, and running the benchmark. For detailed instructions, see our previous blog about running MLPerf v1.1 on bare metal systems.

MLPerf v1.1 Benchmarking 

Benchmarking scenarios

We assessed inference latency and throughput for ResNet50 and BERT models using MLPerf Inference v1.1. The scenarios in the following table identify the number of VMs and corresponding MIG profiles used in performance tests. The total number of tests for each scenario is 57. The results are averaged based on three runs.
Note: We used MLPerf Inference v1.1 for benchmarking but the results shown in this blog are not part of the official MLPerf submissions.

Table 2: Scenarios configuration

ResNet50

ResNet50 (see Deep Residual Learning for Image Recognition) is a widely used deep convolutional neural network for various computer vision applications. This neural network can address the disappearing gradients problem by allowing gradients to traverse the network's layers using the concept of skip connections. The following figure shows an example configuration for ResNet50 inference:

Figure 4- Configuration for running inference using Resnet50 model

The following figure shows ResNet50 inference performance based on the scenarios in Table 2:

Figure 5- ResNet50 Performance throughput of MLPerf Inference v1.1 across various VMs with MIG profiles

Multiple data scientists can use all the available GPU resources while running their individual workloads on separate instances, improving overall system throughput. This result is clearly seen on Scenarios 6 through 8, which contain multiple instances, compared to Scenario 1 which consists of a single instance with the largest MIG profile for A100 80 GB. Scenario 6 achieves the highest overall system throughput (5.77 percent improvement) compared to Scenario 1. Also, Scenario 8 shows seven VMs equipped with individual GPU instances that can be built for up to seven data scientists who can fine-tune their ResNet50 base models.

BERT

BERT (see BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding) is a state-of-the-art language representational model. BERT is essentially a stack of Transformer encoders. It is suitable for neural machine translation, question answering, sentiment analysis, and text summarization, all of which require a working knowledge of the target language.

BERT is trained in two stages:

• Pretrain—During which the model acquires language and context understanding
• Fine-tuning—During which the model acquires task-specific knowledge such as querying and response.

The following figure shows an example configuration for BERT inference:

Figure 6- Configuration for running inference using BERT model

The following figure shows BERT inference performance based on scenarios in Table 2:

Figure 7- BERT Performance throughput of MLPerf Inference v1.1 across various VMs with MIG profiles

Like Resnet50 Inference performance, we clearly see that Scenarios 6 through 8, which contain multiple instances, perform better compared to Scenario 1. Particularly, Scenario 7 achieves the highest overall system throughput (21 percent improvement) compared to Scenario 1 while achieving 99.9 percent accuracy target. Also, Scenario 8 shows seven VMs equipped with individual GPU instances that can be built for up to seven data scientists who want to fine-tune their BERT base models.

Conclusion

In this blog, we describe how to install and configure MLPerf Inference v1.1 on Dell PowerEdge 750xa servers using a VMware-virtualized infrastructure and NVIDIA A100 GPUs. Furthermore, we examine the performance of single- and multi-MIG profiles running on the A100 GPU. If your ML workload is primarily inferencing-focused and response time is not an issue, enabling MIG on the A100 GPU can ensure complete GPU use with maximum throughput. Developers can use VMs with an independent GPU compute allocated to them. Also, in cases where the largest MIG profiles are used, performance is comparable to bare metal systems. Inference results from ResNet50 and BERT models demonstrate that overall system performance using either the whole GPU or multiple VMs with MIG instances hosted on an R750xa system with VMware ESXi and NVIDIA A100 GPUs performed well and produced valid results for MLPerf Inference v1.1. In both the cases, the average throughput and latency are equal. This result confirms that MIG provides predictable latency and throughput independent of other processes operating on the MIG instances on the GPU.

 There is a MIG limitation for GPU profiling on the VMs. Due to the shared nature of the hardware performance across all MIG devices, only one GPU profiling session can run on a VM; parallel GPU profiling sessions on a single VM are not possible.