# Benchmarks

Here we benchmark the training and testing speed of models in MMDetection3D,
with some other open source 3D detection codebases.

## Settings

* Hardwares: 8 NVIDIA Tesla V100 (32G) GPUs, Intel(R) Xeon(R) Gold 6148 CPU @ 2.40GHz
* Software: Python 3.7, CUDA 10.1, cuDNN 7.6.5, PyTorch 1.3, numba 0.48.0.
* Model: Since all the other codebases implements different models, we compare the corresponding models including SECOND, PointPillars, Part-A2, and VoteNet with them separately.
* Metrics: We use the average throughput in iterations of the entire training run and skip the first 50 iterations of each epoch to skip GPU warmup time.

## Main Results

We compare the training speed (samples/s) with other codebases if they implement the similar models. The results are as below, the greater the numbers in the table, the faster of the training process.

| Methods | MMDetection3D |votenet| Det3D | OpenPCDet |
|:-------:|:-------------:|:-----:|:-----:|:---------:|
| VoteNet | 358           |   77  | ×     | ×         |
| PointPillars-car| 141           |   ×  | 140     | ×         |
| PointPillars-3class| 107           |   ×      | ×    |44     |
| SECOND | 40           |   ×      | ×    |30     |
| Part-A2| 17           |   ×      | ×    |14     |

## Details of Comparison

### Modification for Calculating Speed

* __MMDetection3D__: We try to use as similar settings as those of other codebases as possible using [benchmark configs](https://github.com/open-mmlab/MMDetection3D/blob/master/configs/benchmark).

* __Det3D__: For comparison with Det3D, we use the commit [519251e](https://github.com/poodarchu/Det3D/tree/519251e72a5c1fdd58972eabeac67808676b9bb7).

* __OpenPCDet__: For comparison with OpenPCDet, we use the commit [b32fbddb](https://github.com/open-mmlab/OpenPCDet/tree/b32fbddbe06183507bad433ed99b407cbc2175c2).

    For training speed, we add code to record the running time in the file `./tools/train_utils/train_utils.py`. We calculate the speed of each epoch, and report the average speed of all the epochs.
    <details>
    <summary>
    (diff to make it use the same method for benchmarking speed - click to expand)
    </summary>

    ```diff
    diff --git a/tools/train_utils/train_utils.py b/tools/train_utils/train_utils.py
    index 91f21dd..021359d 100644
    --- a/tools/train_utils/train_utils.py
    +++ b/tools/train_utils/train_utils.py
    @@ -2,6 +2,7 @@ import torch
     import os
     import glob
     import tqdm
    +import datetime
     from torch.nn.utils import clip_grad_norm_


    @@ -13,7 +14,10 @@ def train_one_epoch(model, optimizer, train_loader, model_func, lr_scheduler, ac
         if rank == 0:
             pbar = tqdm.tqdm(total=total_it_each_epoch, leave=leave_pbar, desc='train', dynamic_ncols=True)

    +    start_time = None
         for cur_it in range(total_it_each_epoch):
    +        if cur_it > 49 and start_time is None:
    +            start_time = datetime.datetime.now()
             try:
                 batch = next(dataloader_iter)
             except StopIteration:
    @@ -55,9 +59,11 @@ def train_one_epoch(model, optimizer, train_loader, model_func, lr_scheduler, ac
                     tb_log.add_scalar('learning_rate', cur_lr, accumulated_iter)
                     for key, val in tb_dict.items():
                         tb_log.add_scalar('train_' + key, val, accumulated_iter)
    +    endtime = datetime.datetime.now()
    +    speed = (endtime - start_time).seconds / (total_it_each_epoch - 50)
         if rank == 0:
             pbar.close()
    -    return accumulated_iter
    +    return accumulated_iter, speed


     def train_model(model, optimizer, train_loader, model_func, lr_scheduler, optim_cfg,
    @@ -65,6 +71,7 @@ def train_model(model, optimizer, train_loader, model_func, lr_scheduler, optim_
                     lr_warmup_scheduler=None, ckpt_save_interval=1, max_ckpt_save_num=50,
                     merge_all_iters_to_one_epoch=False):
         accumulated_iter = start_iter
    +    speeds = []
         with tqdm.trange(start_epoch, total_epochs, desc='epochs', dynamic_ncols=True, leave=(rank == 0)) as tbar:
             total_it_each_epoch = len(train_loader)
             if merge_all_iters_to_one_epoch:
    @@ -82,7 +89,7 @@ def train_model(model, optimizer, train_loader, model_func, lr_scheduler, optim_
                     cur_scheduler = lr_warmup_scheduler
                 else:
                     cur_scheduler = lr_scheduler
    -            accumulated_iter = train_one_epoch(
    +            accumulated_iter, speed = train_one_epoch(
                     model, optimizer, train_loader, model_func,
                     lr_scheduler=cur_scheduler,
                     accumulated_iter=accumulated_iter, optim_cfg=optim_cfg,
    @@ -91,7 +98,7 @@ def train_model(model, optimizer, train_loader, model_func, lr_scheduler, optim_
                     total_it_each_epoch=total_it_each_epoch,
                     dataloader_iter=dataloader_iter
                 )
    -
    +            speeds.append(speed)
                 # save trained model
                 trained_epoch = cur_epoch + 1
                 if trained_epoch % ckpt_save_interval == 0 and rank == 0:
    @@ -107,6 +114,8 @@ def train_model(model, optimizer, train_loader, model_func, lr_scheduler, optim_
                     save_checkpoint(
                         checkpoint_state(model, optimizer, trained_epoch, accumulated_iter), filename=ckpt_name,
                     )
    +            print(speed)
    +    print(f'*******{sum(speeds) / len(speeds)}******')


     def model_state_to_cpu(model_state):
    ```

    </details>

### VoteNet

* __MMDetection3D__: With release v0.1.0, run

  ```bash
  ./tools/dist_train.sh configs/votenet/votenet_16x8_sunrgbd-3d-10class.py 8 --no-validate
  ```

* __votenet__: At commit [2f6d6d3](https://github.com/facebookresearch/votenet/tree/2f6d6d36ff98d96901182e935afe48ccee82d566), run

  ```bash
  python train.py --dataset sunrgbd --batch_size 16
  ```

### PointPillars-car

* __MMDetection3D__: With release v0.1.0, run

  ```bash
  ./tools/dist_train.sh configs/benchmark/hv_pointpillars_secfpn_3x8_100e_det3d_kitti-3d-car.py 8 --no-validate
  ```

* __Det3D__: At commit [519251e](https://github.com/poodarchu/Det3D/tree/519251e72a5c1fdd58972eabeac67808676b9bb7), use `kitti_point_pillars_mghead_syncbn.py` and run

  ```bash
  ./tools/scripts/train.sh --launcher=slurm --gpus=8
  ```

  Note that the config in train.sh is modified to train point pillars.

  <details>
  <summary>
  (diff to benchmark the similar models - click to expand)
  </summary>

  ```diff
  diff --git a/tools/scripts/train.sh b/tools/scripts/train.sh
  index 3a93f95..461e0ea 100755
  --- a/tools/scripts/train.sh
  +++ b/tools/scripts/train.sh
  @@ -16,9 +16,9 @@ then
   fi

   # Voxelnet
  -python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py examples/second/configs/  kitti_car_vfev3_spmiddlefhd_rpn1_mghead_syncbn.py --work_dir=$SECOND_WORK_DIR
  +# python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py examples/second/configs/  kitti_car_vfev3_spmiddlefhd_rpn1_mghead_syncbn.py --work_dir=$SECOND_WORK_DIR
   # python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py examples/cbgs/configs/  nusc_all_vfev3_spmiddleresnetfhd_rpn2_mghead_syncbn.py --work_dir=$NUSC_CBGS_WORK_DIR
   # python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py examples/second/configs/  lyft_all_vfev3_spmiddleresnetfhd_rpn2_mghead_syncbn.py --work_dir=$LYFT_CBGS_WORK_DIR

   # PointPillars
  -# python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py ./examples/point_pillars/configs/  original_pp_mghead_syncbn_kitti.py --work_dir=$PP_WORK_DIR
  +python -m torch.distributed.launch --nproc_per_node=8 ./tools/train.py ./examples/point_pillars/configs/  kitti_point_pillars_mghead_syncbn.py
  ```

  </details>

### PointPillars-3class

* __MMDetection3D__: With release v0.1.0, run

  ```bash
  ./tools/dist_train.sh configs/benchmark/hv_pointpillars_secfpn_4x8_80e_pcdet_kitti-3d-3class.py 8 --no-validate
  ```

* __OpenPCDet__: At commit [b32fbddb](https://github.com/open-mmlab/OpenPCDet/tree/b32fbddbe06183507bad433ed99b407cbc2175c2), run

  ```bash
  cd tools
  sh scripts/slurm_train.sh ${PARTITION} ${JOB_NAME} 8  --cfg_file ./cfgs/pointpillar.yaml --batch_size 32  --workers 32
  ```

### SECOND

* __MMDetection3D__: With release v0.1.0, run

  ```bash
  ./tools/dist_train.sh configs/benchmark/hv_second_secfpn_4x8_80e_pcdet_kitti-3d-3class.py 8 --no-validate
  ```

* __OpenPCDet__: At commit [b32fbddb](https://github.com/open-mmlab/OpenPCDet/tree/b32fbddbe06183507bad433ed99b407cbc2175c2), run

  ```bash
  cd tools
  ./scripts/slurm_train.sh ${PARTITION} ${JOB_NAME} 8  --cfg_file ./cfgs/second.yaml --batch_size 32  --workers 32
  ```

### Part-A2

* __MMDetection3D__: With release v0.1.0, run

  ```bash
  ./tools/dist_train.sh configs/benchmark/hv_PartA2_secfpn_4x8_cyclic_80e_pcdet_kitti-3d-3class.py 8 --no-validate
  ```

* __OpenPCDet__: At commit [b32fbddb](https://github.com/open-mmlab/OpenPCDet/tree/b32fbddbe06183507bad433ed99b407cbc2175c2), train the model by running

  ```bash
  cd tools
  ./scripts/slurm_train.sh ${PARTITION} ${JOB_NAME} 8  --cfg_file ./cfgs/PartA2.yaml --batch_size 32 --workers 32
  ```