DeepLearningExamples/PyTorch/SpeechSynthesis/FastPitch/README.md
2021-07-21 14:39:48 +02:00

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FastPitch 1.0 for PyTorch

This repository provides a script and recipe to train the FastPitch model to achieve state-of-the-art accuracy and is tested and maintained by NVIDIA.

Table Of Contents

Model overview

FastPitch is a fully-parallel transformer architecture with prosody control over pitch and individual phoneme duration. It is one of two major components in a neural, text-to-speech (TTS) system:

Such two-component TTS system is able to synthesize natural sounding speech from raw transcripts.

The FastPitch model generates mel-spectrograms and predicts a pitch contour from raw input text. Some of the capabilities of FastPitch are presented on the website with samples.

Speech synthesized with FastPitch has state-of-the-art quality, and does not suffer from missing/repeating phrases like Tacotron2 does. This is reflected in Mean Opinion Scores (details).

Model Mean Opinion Score (MOS)
Tacotron2 3.946 ± 0.134
FastPitch 4.080 ± 0.133

The FastPitch model is based on the FastSpeech model. The main differences between FastPitch and FastSpeech are that FastPitch:

  • explicitly learns to predict the pitch contour,
  • pitch conditioning removes harsh sounding artifacts and provides faster convergence,
  • no need for distilling mel-spectrograms with a teacher model,
  • character durations are extracted with a pre-trained Tacotron 2 model.

The FastPitch model is similar to FastSpeech2, which has been developed concurrently. FastPitch averages pitch values over input tokens, and does not use additional conditioning such as the energy.

FastPitch is trained on a publicly available LJ Speech dataset.

This model is trained with mixed precision using Tensor Cores on Volta, Turing, and the NVIDIA Ampere GPU architectures. Therefore, researchers can get results from 2.0x to 2.7x faster than training without Tensor Cores, while experiencing the benefits of mixed precision training. This model is tested against each NGC monthly container release to ensure consistent accuracy and performance over time.

Model architecture

FastPitch is a fully feedforward Transformer model that predicts mel-spectrograms from raw text (Figure 1). The entire process is parallel, which means that all input letters are processed simultaneously to produce a full mel-spectrogram in a single forward pass.

FastPitch model architecture

Figure 1. Architecture of FastPitch (source). The model is composed of a bidirectional Transformer backbone (also known as a Transformer encoder), a pitch predictor, and a duration predictor. After passing through the first *N* Transformer blocks, encoding, the signal is augmented with pitch information and discretely upsampled. Then it goes through another set of *N* Transformer blocks, with the goal of smoothing out the upsampled signal, and constructing a mel-spectrogram.

Default configuration

The FastPitch model supports multi-GPU and mixed precision training with dynamic loss scaling (see Apex code here), as well as mixed precision inference.

The following features were implemented in this model:

  • data-parallel multi-GPU training,
  • dynamic loss scaling with backoff for Tensor Cores (mixed precision) training,
  • gradient accumulation for reproducible results regardless of the number of GPUs.

To speed-up FastPitch training, reference mel-spectrograms, character durations, and pitch cues are generated during the pre-processing step and read directly from the disk during training. For more information on data pre-processing refer to Dataset guidelines and the paper.

Feature support matrix

The following features are supported by this model.

Feature FastPitch
AMP Yes
Apex DistributedDataParallel Yes

Features

AMP - a tool that enables Tensor Core-accelerated training. For more information, refer to Enabling mixed precision.

Apex DistributedDataParallel - a module wrapper that enables easy multiprocess distributed data parallel training, similar to torch.nn.parallel.DistributedDataParallel. DistributedDataParallel is optimized for use with NCCL. It achieves high performance by overlapping communication with computation during backward() and bucketing smaller gradient transfers to reduce the total number of transfers required.

Mixed precision training

Mixed precision is the combined use of different numerical precisions in a computational method. Mixed precision training offers significant computational speedup by performing operations in half-precision format while storing minimal information in single-precision to retain as much information as possible in critical parts of the network. Since the introduction of Tensor Cores in Volta, and following with both the Turing and Ampere architectures, significant training speedups are experienced by switching to mixed precision -- up to 3x overall speedup on the most arithmetically intense model architectures. Using mixed precision training requires two steps:

  1. Porting the model to use the FP16 data type where appropriate.
  2. Adding loss scaling to preserve small gradient values.

The ability to train deep learning networks with lower precision was introduced in the Pascal architecture and first supported in CUDA 8 in the NVIDIA Deep Learning SDK.

For information about:

Enabling mixed precision

Mixed precision is enabled in PyTorch by using the Automatic Mixed Precision (AMP) library from APEX that casts variables to half-precision upon retrieval, while storing variables in single-precision format. Furthermore, to preserve small gradient magnitudes in backpropagation, a loss scaling step must be included when applying gradients. In PyTorch, loss scaling can be easily applied by using the scale_loss() method provided by AMP. The scaling value to be used can be dynamic or fixed.

By default, the scripts/train.sh script will run in full precision.To launch mixed precision training with Tensor Cores, either set env variable AMP=true when using scripts/train.sh, or add --amp flag when directly executing train.py without the helper script.

To enable mixed precision, the following steps were performed:

  • Import AMP from APEX:

    from apex import amp
    
  • Initialize AMP:

    model, optimizer = amp.initialize(model, optimizer, opt_level="O1")
    
  • If running on multi-GPU, wrap the model with DistributedDataParallel:

    from apex.parallel import DistributedDataParallel as DDP
    model = DDP(model)
    
  • Scale loss before backpropagation (assuming loss is stored in a variable called losses):

    • Default backpropagate for FP32:

      losses.backward()
      
    • Scale loss and backpropagate with AMP:

      with optimizer.scale_loss(losses) as scaled_losses:
          scaled_losses.backward()
      

Enabling TF32

TensorFloat-32 (TF32) is the new math mode in NVIDIA A100 GPUs for handling the matrix math also called tensor operations. TF32 running on Tensor Cores in A100 GPUs can provide up to 10x speedups compared to single-precision floating-point math (FP32) on Volta GPUs.

TF32 Tensor Cores can speed up networks using FP32, typically with no loss of accuracy. It is more robust than FP16 for models which require high dynamic range for weights or activations.

For more information, refer to the TensorFloat-32 in the A100 GPU Accelerates AI Training, HPC up to 20x blog post.

TF32 is supported in the NVIDIA Ampere GPU architecture and is enabled by default.

Glossary

Character duration The time during which a character is being articulated. Could be measured in milliseconds, mel-spectrogram frames, etc. Some characters are not pronounced, and thus have 0 duration.

Forced alignment Segmentation of a recording into lexical units like characters, words, or phonemes. The segmentation is hard and defines exact starting and ending times for every unit.

Fundamental frequency The lowest vibration frequency of a periodic soundwave, for example, produced by a vibrating instrument. It is perceived as the loudest. In the context of speech, it refers to the frequency of vibration of vocal chords. Abbreviated as f0.

Pitch A perceived frequency of vibration of music or sound.

Transformer The paper Attention Is All You Need introduces a novel architecture called Transformer, which repeatedly applies the attention mechanism. It transforms one sequence into another.

Setup

The following section lists the requirements that you need to meet in order to start training the FastPitch model.

Requirements

This repository contains Dockerfile which extends the PyTorch NGC container and encapsulates some dependencies. Aside from these dependencies, ensure you have the following components:

For more information about how to get started with NGC containers, see the following sections from the NVIDIA GPU Cloud Documentation and the Deep Learning Documentation:

For those unable to use the PyTorch NGC container, to set up the required environment or create your own container, see the versioned NVIDIA Container Support Matrix.

Quick Start Guide

To train your model using mixed or TF32 precision with Tensor Cores or using FP32, perform the following steps using the default parameters of the FastPitch model on the LJSpeech 1.1 dataset. For the specifics concerning training and inference, see the Advanced section. Pre-trained FastPitch models are available for download on NGC.

  1. Clone the repository.

    git clone https://github.com/NVIDIA/DeepLearningExamples.git
    cd DeepLearningExamples/PyTorch/SpeechSynthesis/FastPitch
    
  2. Build and run the FastPitch PyTorch NGC container.

    By default the container will use all available GPUs.

    bash scripts/docker/build.sh
    bash scripts/docker/interactive.sh
    
  3. Download and preprocess the dataset.

    Use the scripts to automatically download and preprocess the training, validation and test datasets:

    bash scripts/download_dataset.sh
    bash scripts/prepare_dataset.sh
    

    The data is downloaded to the ./LJSpeech-1.1 directory (on the host). The ./LJSpeech-1.1 directory is mounted under the /workspace/fastpitch/LJSpeech-1.1 location in the NGC container. The complete dataset has the following structure:

    ./LJSpeech-1.1
    ├── durations        # Character durations estimates for forced alignment training
    ├── mels             # Pre-calculated target mel-spectrograms
    ├── metadata.csv     # Mapping of waveforms to utterances
    ├── pitch_char       # Average per-character fundamental frequencies for input utterances
    ├── pitch_char_stats__ljs_audio_text_train_filelist.json    # Mean and std of pitch for training data
    ├── README
    └── wavs             # Raw waveforms
    
  4. Start training.

    bash scripts/train.sh
    

    The training will produce a FastPitch model capable of generating mel-spectrograms from raw text. It will be serialized as a single .pt checkpoint file, along with a series of intermediate checkpoints. The script is configured for 8x GPU with at least 16GB of memory. Consult Training process and example configs to adjust to a different configuration or enable Automatic Mixed Precision.

  5. Start validation/evaluation.

    Ensure your training loss values are comparable to those listed in the table in the Results section. Note that the validation loss is evaluated with ground truth durations for letters (not the predicted ones). The loss values are stored in the ./output/nvlog.json log file, ./output/{train,val,test} as TensorBoard logs, and printed to the standard output (stdout) during training. The main reported loss is a weighted sum of losses for mel-, pitch-, and duration- predicting modules.

    The audio can be generated by following the Inference process section below. The synthesized audio should be similar to the samples in the ./audio directory.

  6. Start inference/predictions.

    To synthesize audio, you will need a WaveGlow model, which generates waveforms based on mel-spectrograms generated with FastPitch. By now, a pre-trained model should have been downloaded by the scripts/download_dataset.sh script. Alternatively, to train WaveGlow from scratch, follow the instructions in NVIDIA/DeepLearningExamples/Tacotron2 and replace the checkpoint in the ./pretrained_models/waveglow directory.

    You can perform inference using the respective .pt checkpoints that are passed as --fastpitch and --waveglow arguments:

    python inference.py --cuda \
                        --fastpitch output/<FastPitch checkpoint> \
                        --waveglow pretrained_models/waveglow/<WaveGlow checkpoint> \
                        --wn-channels 256 \
                        -i phrases/devset10.tsv \
                        -o output/wavs_devset10
    

    The speech is generated from a file passed with the -i argument, with one utterance per line:

    `<output wav file name>|<utterance>`
    

To run inference in mixed precision, use the --amp flag. The output audio will be stored in the path specified by the -o argument. Consult the inference.py to learn more options, such as setting the batch size.

Advanced

The following sections provide greater details of the dataset, running training and inference, and the training results.

Scripts and sample code

The repository holds code for FastPitch (training and inference) and WaveGlow (inference only). The code specific to a particular model is located in that models directory - ./fastpitch and ./waveglow - and common functions live in the ./common directory. The model-specific scripts are as follows:

  • <model_name>/model.py - the model architecture, definition of forward and inference functions
  • <model_name>/arg_parser.py - argument parser for parameters specific to a given model
  • <model_name>/data_function.py - data loading functions
  • <model_name>/loss_function.py - loss function for the model

The common scripts contain layer definitions common to both models (common/layers.py), some utility scripts (common/utils.py) and scripts for audio processing (common/audio_processing.py and common/stft.py).

In the root directory ./ of this repository, the ./train.py script is used for training while inference can be executed with the ./inference.py script. The scripts ./models.py, ./data_functions.py and ./loss_functions.py call the respective scripts in the <model_name> directory, depending on what the model is trained using the train.py script.

The repository is structured similarly to the NVIDIA Tacotron2 Deep Learning example, so that they could be combined in more advanced use cases.

Parameters

In this section, we list the most important hyperparameters and command-line arguments, together with their default values that are used to train FastPitch.

  • --epochs - number of epochs (default: 1500)

  • --learning-rate - learning rate (default: 0.1)

  • --batch-size - batch size (default: 32)

  • --amp - use mixed precision training (default: disabled)

  • --pitch-predictor-loss-scale - rescale the loss of the pitch predictor module to dampen its influence on the shared feedforward transformer blocks

  • --duration-predictor-loss-scale - rescale the loss of the duration predictor module to dampen its influence on the shared feedforward transformer blocks

Command-line options

To see the full list of available options and their descriptions, use the -h or --help command line option, for example:

python train.py --help

The following example output is printed when running the model:

DLL 2020-03-30 10:41:12.562594 - epoch    1 | iter   1/19 | loss 36.99 | mel loss 35.25 |  142370.52 items/s | elapsed 2.50 s | lrate 1.00E-01 -> 3.16E-06
DLL 2020-03-30 10:41:13.202835 - epoch    1 | iter   2/19 | loss 37.26 | mel loss 35.98 |  561459.27 items/s | elapsed 0.64 s | lrate 3.16E-06 -> 6.32E-06
DLL 2020-03-30 10:41:13.831189 - epoch    1 | iter   3/19 | loss 36.93 | mel loss 35.41 |  583530.16 items/s | elapsed 0.63 s | lrate 6.32E-06 -> 9.49E-06

Getting the data

The FastPitch and WaveGlow models were trained on the LJSpeech-1.1 dataset. The ./scripts/download_dataset.sh script will automatically download and extract the dataset to the ./LJSpeech-1.1 directory.

Dataset guidelines

The LJSpeech dataset has 13,100 clips that amount to about 24 hours of speech of a single, female speaker. Since the original dataset does not define a train/dev/test split of the data, we provide a split in the form of three file lists:

./filelists
├── ljs_mel_dur_pitch_text_test_filelist.txt
├── ljs_mel_dur_pitch_text_train_filelist.txt
└── ljs_mel_dur_pitch_text_val_filelist.txt

NOTE: When combining FastPitch/WaveGlow with external models trained on LJSpeech-1.1, make sure that your train/dev/test split matches. Different organizations may use custom splits. A mismatch poses a risk of leaking the training data through model weights during validation and testing.

FastPitch predicts character durations just like FastSpeech does. This calls for training with forced alignments, expressed as the number of output mel-spectrogram frames for every input character. To this end, a pre-trained Tacotron 2 model is used. Its attention matrix relates the input characters with the output mel-spectrogram frames.

For every mel-spectrogram frame, its fundamental frequency in Hz is estimated with Praat. Those values are then averaged over every character, in order to provide sparse pitch cues for the model. Character boundaries are calculated from durations extracted previously with Tacotron 2.

Pitch estimates extracted with Praat

Figure 2. Pitch estimates for mel-spectrogram frames of phrase "in being comparatively" (in blue) averaged over characters (in red). Silent letters have duration 0 and are omitted.

Multi-dataset

Follow these steps to use datasets different from the default LJSpeech dataset.

  1. Prepare a directory with .wav files.

    ./my_dataset
    └── wavs
    
  2. Prepare filelists with transcripts and paths to .wav files. They define training/validation split of the data (test is currently unused):

    ./filelists
    ├── my_dataset_mel_ali_pitch_text_train_filelist.txt
    └── my_dataset_mel_ali_pitch_text_val_filelist.txt
    

Those filelists should list a single utterance per line as:

`<audio file path>|<transcript>`

The <audio file path> is the relative path to the path provided by the --dataset-path option of train.py.

  1. Run the pre-processing script to calculate mel-spectrograms, durations and pitch:
    python extract_mels.py --cuda \
                           --dataset-path ./my_dataset \
                           --wav-text-filelist ./filelists/my_dataset_mel_ali_pitch_text_train_filelist.txt \
                           --extract-mels \
                           --extract-durations \
                           --extract-pitch-char \
                           --tacotron2-checkpoint ./pretrained_models/tacotron2/state_dict.pt"
    
    python extract_mels.py --cuda \
                           --dataset-path ./my_dataset \
                           --wav-text-filelist ./filelists/my_dataset_mel_ali_pitch_text_val_filelist.txt \
                           --extract-mels \
                           --extract-durations \
                           --extract-pitch-char \
                           --tacotron2-checkpoint ./pretrained_models/tacotron2/state_dict.pt"
    

In order to use the prepared dataset, pass the following to the train.py script:

--dataset-path ./my_dataset` \
--training-files ./filelists/my_dataset_mel_ali_pitch_text_train_filelist.txt \
--validation files ./filelists/my_dataset_mel_ali_pitch_text_val_filelist.txt

Training process

FastPitch is trained to generate mel-spectrograms from raw text input. It uses short time Fourier transform (STFT) to generate target mel-spectrograms from audio waveforms to be the training targets.

The training loss is averaged over an entire training epoch, whereas the validation loss is averaged over the validation dataset. Performance is reported in total output mel-spectrogram frames per second and recorded as train_frames/s (after each iteration) and avg_train_frames/s (averaged over epoch) in the output log file ./output/nvlog.json. The result is averaged over an entire training epoch and summed over all GPUs that were included in the training.

The scripts/train.sh script is configured for 8x GPU with at least 16GB of memory: bash --batch-size 32 --gradient-accumulation-steps 1 In a single accumulated step, there are batch_size x gradient_accumulation_steps x GPUs = 256 examples being processed in parallel. With a smaller number of GPUs, increase --gradient_accumulation_steps to keep this relation satisfied, e.g., through env variables bash NUM_GPUS=4 GRAD_ACCUMULATION=2 bash scripts/train.sh With automatic mixed precision (AMP), a larger batch size fits in 16GB of memory: bash NUM_GPUS=4 GRAD_ACCUMULATION=1 BS=64 AMP=true bash scripts/train.sh

Inference process

You can run inference using the ./inference.py script. This script takes text as input and runs FastPitch and then WaveGlow inference to produce an audio file. It requires pre-trained checkpoints of both models and input text as a text file, with one phrase per line.

Pre-trained FastPitch models are available for download on NGC.

Having pre-trained models in place, run the sample inference on LJSpeech-1.1 test-set with:

bash scripts/inference_example.sh

Examine the inference_example.sh script to adjust paths to pre-trained models, and call python inference.py --help to learn all available options. By default, synthesized audio samples are saved in ./output/audio_* folders.

FastPitch allows us to linearly adjust the pace of synthesized speech like FastSpeech. For instance, pass --pace 0.5 for a twofold decrease in speed.

For every input character, the model predicts a pitch cue - an average pitch over a character in Hz. Pitch can be adjusted by transforming those pitch cues. A few simple examples are provided below.

Transformation Flag Samples
- - link
Amplify pitch wrt. to the mean pitch --pitch-transform-amplify link
Invert pitch wrt. to the mean pitch --pitch-transform-invert link
Raise/lower pitch by --pitch-transform-shift <hz> link
Flatten the pitch to a constant value --pitch-transform-flatten link
Change the pace of speech (1.0 = unchanged) --pace <value> link

The flags can be combined. Modify these functions directly in the inference.py script to gain more control over the final result.

You can find all the available options by calling python inference.py --help. More examples are presented on the website with samples.

Performance

The performance measurements in this document were conducted at the time of publication and may not reflect the performance achieved from NVIDIAs latest software release. For the most up-to-date performance measurements, go to NVIDIA Data Center Deep Learning Product Performance.

Benchmarking

The following section shows how to run benchmarks measuring the model performance in training and inference mode.

Training performance benchmark

To benchmark the training performance on a specific batch size, run:

  • NVIDIA DGX A100 (8x A100 40GB)

        AMP=true NUM_GPUS=1 BS=128 GRAD_ACCUMULATION=2 EPOCHS=10 bash scripts/train.sh
        AMP=true NUM_GPUS=8 BS=32 GRAD_ACCUMULATION=1 EPOCHS=10 bash scripts/train.sh
        NUM_GPUS=1 BS=128 GRAD_ACCUMULATION=2 EPOCHS=10 bash scripts/train.sh
        NUM_GPUS=8 BS=32 GRAD_ACCUMULATION=1 EPOCHS=10 bash scripts/train.sh
    
  • NVIDIA DGX-1 (8x V100 16GB)

        AMP=true NUM_GPUS=1 BS=64 GRAD_ACCUMULATION=4 EPOCHS=10 bash scripts/train.sh
        AMP=true NUM_GPUS=8 BS=32 GRAD_ACCUMULATION=1 EPOCHS=10 bash scripts/train.sh
        NUM_GPUS=1 BS=32 GRAD_ACCUMULATION=8 EPOCHS=10 bash scripts/train.sh
        NUM_GPUS=8 BS=32 GRAD_ACCUMULATION=1 EPOCHS=10 bash scripts/train.sh
    

Each of these scripts runs for 10 epochs and for each epoch measures the average number of items per second. The performance results can be read from the nvlog.json files produced by the commands.

Inference performance benchmark

To benchmark the inference performance on a specific batch size, run:

  • For FP16

    AMP=true BS_SEQUENCE=”1 4 8” REPEATS=100 bash scripts/inference_benchmark.sh
    
  • For FP32 or TF32

    BS_SEQUENCE=”1 4 8” REPEATS=100 bash scripts/inference_benchmark.sh
    

The output log files will contain performance numbers for the FastPitch model (number of output mel-spectrogram frames per second, reported as generator_frames/s w ) and for WaveGlow (number of output samples per second, reported as waveglow_samples/s). The inference.py script will run a few warm-up iterations before running the benchmark. Inference will be averaged over 100 runs, as set by the REPEATS env variable.

Results

The following sections provide details on how we achieved our performance and accuracy in training and inference.

Training accuracy results

Training accuracy: NVIDIA DGX A100 (8x A100 40GB)

Our results were obtained by running the ./platform/DGXA100_FastPitch_{AMP,TF32}_8GPU.sh training script in the 20.06-py3 NGC container on NVIDIA DGX A100 (8x A100 40GB) GPUs.

Loss (Model/Epoch) 50 250 500 750 1000 1250 1500
FastPitch AMP 0.503 0.252 0.214 0.202 0.193 0.188 0.184
FastPitch TF32 0.500 0.252 0.215 0.201 0.193 0.187 0.183
Training accuracy: NVIDIA DGX-1 (8x V100 16GB)

Our results were obtained by running the ./platform/DGX1_FastPitch_{AMP,FP32}_8GPU.sh training script in the PyTorch 20.06-py3 NGC container on NVIDIA DGX-1 with 8x V100 16GB GPUs.

All of the results were produced using the train.py script as described in the Training process section of this document.

Loss (Model/Epoch) 50 250 500 750 1000 1250 1500
FastPitch AMP 0.499 0.250 0.211 0.198 0.190 0.184 0.180
FastPitch FP32 0.503 0.251 0.214 0.201 0.192 0.186 0.182
Loss curves

Training performance results

Training performance: NVIDIA DGX A100 (8x A100 40GB)

Our results were obtained by running the ./platform/DGXA100_FastPitch_{AMP,TF32}_8GPU.sh training script in the 20.06-py3 NGC container on NVIDIA DGX A100 (8x A100 40GB) GPUs. Performance numbers, in output mel-scale spectrogram frames per second, were averaged over an entire training epoch.

Number of GPUs Batch size per GPU Frames/s with mixed precision Frames/s with TF32 Speed-up with mixed precision Multi-GPU strong scaling with mixed precision Multi-GPU strong scaling with TF32
1 128@AMP, 128@TF32 164955 113725 1.45 1.00 1.00
4 64@AMP, 64@TF32 619527 435951 1.42 3.76 3.83
8 32@AMP, 32@TF32 1040206 643569 1.62 6.31 5.66
Expected training time

The following table shows the expected training time for convergence for 1500 epochs:

Number of GPUs Batch size per GPU Time to train with mixed precision (Hrs) Time to train with TF32 (Hrs) Speed-up with mixed precision
1 128@AMP, 128@TF32 18.5 26.6 1.44
4 64@AMP, 64@TF32 5.5 7.5 1.36
8 32@AMP, 32@TF32 3.6 5.3 1.47
Training performance: NVIDIA DGX-1 (8x V100 16GB)

Our results were obtained by running the ./platform/DGX1_FastPitch_{AMP,FP32}_8GPU.sh training script in the PyTorch 20.06-py3 NGC container on NVIDIA DGX-1 with 8x V100 16GB GPUs. Performance numbers, in output mel-scale spectrogram frames per second, were averaged over an entire training epoch.

Number of GPUs Batch size per GPU Frames/s with mixed precision Frames/s with FP32 Speed-up with mixed precision Multi-GPU strong scaling with mixed precision Multi-GPU strong scaling with FP32
1 64@AMP, 32@FP32 110370 41066 2.69 1.00 1.00
4 64@AMP, 32@FP32 402368 153853 2.62 3.65 3.75
8 32@AMP, 32@FP32 570968 296767 1.92 5.17 7.23

To achieve these same results, follow the steps in the Quick Start Guide.

Expected training time

The following table shows the expected training time for convergence for 1500 epochs:

Number of GPUs Batch size per GPU Time to train with mixed precision (Hrs) Time to train with FP32 (Hrs) Speed-up with mixed precision
1 64@AMP, 32@FP32 27.6 72.7 2.63
4 64@AMP, 32@FP32 8.2 20.3 2.48
8 32@AMP, 32@FP32 5.9 10.9 1.85

Note that most of the quality is achieved after the initial 500 epochs.

Inference performance results

The following tables show inference statistics for the FastPitch and WaveGlow text-to-speech system, gathered from 100 inference runs. Latency is measured from the start of FastPitch inference to the end of WaveGlow inference. Throughput is measured as the number of generated audio samples per second at 22KHz. RTF is the real-time factor which denotes the number of seconds of speech generated in a second of wall-clock time, per input utterance. The used WaveGlow model is a 256-channel model.

Note that performance numbers are related to the length of input. The numbers reported below were taken with a moderate length of 128 characters. Longer utterances yield higher RTF, as the generator is fully parallel.

Inference performance: NVIDIA DGX A100 (1x A100 40GB)

Our results were obtained by running the ./scripts/inference_benchmark.sh inferencing benchmarking script in the 20.06-py3 NGC container on NVIDIA DGX A100 (1x A100 40GB) GPU.

Batch size Precision Avg latency (s) Latency tolerance interval 90% (s) Latency tolerance interval 95% (s) Latency tolerance interval 99% (s) Throughput (samples/sec) Speed-up with mixed precision Avg RTF
1 FP16 0.106 0.106 0.106 0.107 1,636,913 1.60 74.24
4 FP16 0.390 0.391 0.391 0.391 1,780,764 1.55 20.19
8 FP16 0.758 0.758 0.758 0.758 1,832,544 1.52 10.39
1 TF32 0.170 0.170 0.170 0.170 1,020,894 - 46.30
4 TF32 0.603 0.603 0.603 0.603 1,150,598 - 13.05
8 TF32 1.153 1.154 1.154 1.154 1,202,463 - 6.82
Inference performance: NVIDIA DGX-1 (1x V100 16GB)

Our results were obtained by running the ./scripts/inference_benchmark.sh script in the PyTorch 20.06-py3 NGC container. The input utterance has 128 characters, synthesized audio has 8.05 s.

Batch size Precision Avg latency (s) Latency tolerance interval 90% (s) Latency tolerance interval 95% (s) Latency tolerance interval 99% (s) Throughput (samples/sec) Speed-up with mixed precision Avg RTF
1 FP16 0.193 0.194 0.194 0.194 902,960 2.35 40.95
4 FP16 0.610 0.613 0.613 0.614 1,141,207 2.78 12.94
8 FP16 1.157 1.161 1.161 1.162 1,201,684 2.68 6.81
1 FP32 0.453 0.455 0.456 0.457 385,027 - 17.46
4 FP32 1.696 1.703 1.705 1.707 411,124 - 4.66
8 FP32 3.111 3.118 3.120 3.122 448,275 - 2.54
Inference performance: NVIDIA T4

Our results were obtained by running the ./scripts/inference_benchmark.sh script in the PyTorch 20.06-py3 NGC container. The input utterance has 128 characters, synthesized audio has 8.05 s.

Batch size Precision Avg latency (s) Latency tolerance interval 90% (s) Latency tolerance interval 95% (s) Latency tolerance interval 99% (s) Throughput (samples/sec) Speed-up with mixed precision Avg RTF
1 FP16 0.533 0.540 0.541 0.543 326,471 2.56 14.81
4 FP16 2.292 2.302 2.304 2.308 304,283 2.38 3.45
8 FP16 4.564 4.578 4.580 4.585 305,568 1.99 1.73
1 FP32 1.365 1.383 1.387 1.394 127,765 - 5.79
4 FP32 5.192 5.214 5.218 5.226 134,309 - 1.52
8 FP32 9.09 9.11 9.114 9.122 153,434 - 0.87

Release notes

We're constantly refining and improving our performance on AI and HPC workloads even on the same hardware with frequent updates to our software stack. For our latest performance data please refer to these pages for AI and HPC benchmarks.

Changelog

October 2020

  • Added multispeaker capabilities
  • Updated text processing module

June 2020

  • Updated performance tables to include A100 results

May 2020

  • Initial release

Known issues

There are no known issues with this model with this model.