keras LSTM 层训练时间太长

每当我在 Keras 上尝试 LSTM 模型时，似乎由于训练时间过长，该模型无法训练。

例如，像这样的模型每步需要 80 秒来训练：

def create_model(self):
        inputs = {}
        inputs['input'] = []
        lstm = []
        placeholder = {}
        for tf, v in self.env.timeframes.items():
            inputs[tf] = Input(shape = v['shape'], name = tf)
            lstm.append(LSTM(8)(inputs[tf]))
            inputs['input'].append(inputs[tf])
        account = Input(shape = (3,), name = 'account')
        account_ = Dense(8, activation = 'relu')(account)
        dt = Input(shape = (7,), name = 'dt')
        dt_ = Dense(16, activation = 'relu')(dt)
        inputs['input'].extend([account, dt])

        data = Concatenate(axis = 1)(lstm)
        data = Dense(128, activation = 'relu')(data)
        y = Concatenate(axis = 1)([data, account, dt])
        y = Dense(256, activation = 'relu')(y)
        y = Dense(64, activation = 'relu')(y)
        y = Dense(16, activation = 'relu')(y)
        output = Dense(3, activation = 'linear')(y)

        model = Model(inputs = inputs['input'], outputs = output)
        model.compile(loss = 'mse', optimizer = 'adam', metrics = ['mae'])
        return model

而使用 Flatten + Dense 替代 LSTM 的模型如下：

def create_model(self):
        inputs = {}
        inputs['input'] = []
        lstm = []
        placeholder = {}
        for tf, v in self.env.timeframes.items():
            inputs[tf] = Input(shape = v['shape'], name = tf)
            #lstm.append(LSTM(8)(inputs[tf]))
            placeholder[tf] = Flatten()(inputs[tf])
            lstm.append(Dense(32, activation = 'relu')(placeholder[tf]))
            inputs['input'].append(inputs[tf])
        account = Input(shape = (3,), name = 'account')
        account_ = Dense(8, activation = 'relu')(account)
        dt = Input(shape = (7,), name = 'dt')
        dt_ = Dense(16, activation = 'relu')(dt)
        inputs['input'].extend([account, dt])

        data = Concatenate(axis = 1)(lstm)
        data = Dense(128, activation = 'relu')(data)
        y = Concatenate(axis = 1)([data, account, dt])
        y = Dense(256, activation = 'relu')(y)
        y = Dense(64, activation = 'relu')(y)
        y = Dense(16, activation = 'relu')(y)
        output = Dense(3, activation = 'linear')(y)

        model = Model(inputs = inputs['input'], outputs = output)
        model.compile(loss = 'mse', optimizer = 'adam', metrics = ['mae'])
        return model

每步训练需要 45-50 毫秒。

模型中是否存在导致此问题的问题？或者这是否与该模型的运行速度一样快？

-- self.env.timeframes 看起来像这样：有 9 个项目的字典

timeframes = {
            's1': {
                'lookback': 86400,
                'word': '1 s',
                'unit': 1,
                'offset': 12
                },
            's5': {
                'lookback': 200,
                'word': '5 s',
                'unit': 5,
                'offset': 2
                },
            'm1': {
                'lookback': 100,
                'word': '1 min',
                'unit': 60,
                'offset': 0
                },
            'm5': {
                'lookback': 100,
                'word': '5 min',
                'unit': 300,
                'offset': 0
                },
            'm30': {
                'lookback': 100,
                'word': '30 min',
                'unit': 1800,
                'offset': 0
                },
            'h1': {
                'lookback': 200,
                'word': '1 h',
                'unit': 3600,
                'offset': 0
                },
            'h4': {
                'lookback': 200,
                'word': '4 h',
                'unit': 14400,
                'offset': 0
                },
            'h12': {
                'lookback': 100,
                'word': '12 h',
                'unit': 43200,
                'offset': 0
                },
            'd1': {
                'lookback': 200,
                'word': '1 d',
                'unit': 86400,
                'offset': 0
                }
            }

提示中的 GPU 信息 -

2018-06-30 07:35:16.204320: I T:\src\github\tensorflow\tensorflow\core\platform\cpu_feature_guard.cc:140] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2
2018-06-30 07:35:16.495832: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:1356] Found device 0 with properties:
name: GeForce GTX 1080 major: 6 minor: 1 memoryClockRate(GHz): 1.86
pciBusID: 0000:01:00.0
totalMemory: 8.00GiB freeMemory: 6.59GiB
2018-06-30 07:35:16.495981: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:1435] Adding visible gpu devices: 0
2018-06-30 07:35:16.956743: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:923] Device interconnect StreamExecutor with strength 1 edge matrix:
2018-06-30 07:35:16.956827: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:929]      0
2018-06-30 07:35:16.957540: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:942] 0:   N
2018-06-30 07:35:16.957865: I T:\src\github\tensorflow\tensorflow\core\common_runtime\gpu\gpu_device.cc:1053] Created TensorFlow device (/job:localhost/replica:0/task:0/device:GPU:0 with 6370 MB memory) -> physical GPU (device: 0, name: GeForce GTX 1080, pci bus id: 0000:01:00.0, compute capability: 6.1)

如果您使用 GPU，请将所有 LSTM 层替换为 CuDNNLSTM 层。您可以从以下位置导入它keras.layers:

from keras.layers import  CuDNNLSTM

def create_model(self):
    inputs = {}
    inputs['input'] = []
    lstm = []
    placeholder = {}
    for tf, v in self.env.timeframes.items():
        inputs[tf] = Input(shape = v['shape'], name = tf)
        lstm.append(CuDNNLSTM(8)(inputs[tf]))
        inputs['input'].append(inputs[tf])
    account = Input(shape = (3,), name = 'account')
    account_ = Dense(8, activation = 'relu')(account)
    dt = Input(shape = (7,), name = 'dt')
    dt_ = Dense(16, activation = 'relu')(dt)
    inputs['input'].extend([account, dt])

    data = Concatenate(axis = 1)(lstm)
    data = Dense(128, activation = 'relu')(data)
    y = Concatenate(axis = 1)([data, account, dt])
    y = Dense(256, activation = 'relu')(y)
    y = Dense(64, activation = 'relu')(y)
    y = Dense(16, activation = 'relu')(y)
    output = Dense(3, activation = 'linear')(y)

    model = Model(inputs = inputs['input'], outputs = output)
    model.compile(loss = 'mse', optimizer = 'adam', metrics = ['mae'])
    return model

以下是更多信息：https://keras.io/layers/recurrent/#cudnnlstm

这将显着加快模型速度 =)