Your team is developing a custom Deep Neural Network model using TensorFlow on AI Platform to predict medical diagnoses from diagnostic images. This task is complex and resource-intensive, requiring optimization for both accuracy and computational efficiency. Given the constraints of limited computational resources and the need for rapid iteration, you decide to utilize GCP's hyperparameter tuning feature to optimize your model. Which two parameters must you specify to effectively guide the hyperparameter tuning process towards achieving the best model performance under these constraints? (Choose two)