Same for me. After updating to Sonoma from Ventura my training runs 5 times slower than before. I also noticed that the GPU is no longer used, despite the message “2023-10-03 19:35:08.186175: I tensorflow/core/grappler/optimizers/custom_graph_optimizer_registry.cc:117] Plugin optimizer for device_type GPU is enabled.” I have installed and reinstalled tensorflow-metal, and if I run this code: import tensorflow as tf cifar = tf.keras.datasets.cifar100 (x_train, y_train), (x_test, y_test) = cifar.load_data() model = tf.keras.applications.ResNet50( include_top=True, weights=None, input_shape=(32, 32, 3), classes=100,) model.summary() loss_fn = tf.keras.losses.SparseCategoricalCrossentropy(from_logits=False) model.compile(optimizer="adam", loss=loss_fn, metrics=["accuracy"]) model.fit(x_train, y_train, epochs=5, batch_size=64) I see from the activity monitor that the GPU is fully utilized. However, when I run another training which took about 11 seconds per batch on Ventura, it now takes more than 56 seconds per batch, and the GPU is utilized only at around 20% (before it was up to 98%). I have also already set the optimizer to tf.keras.optimizers.legacy.Adam, as suggested by the warning. Still no success in recreating the performances experienced in MacOS Ventura.