Memory-efficient version.

def attention_lm_moe_memory_efficient():
  """Memory-efficient version."""
  hparams = attention_lm_moe_large()
  hparams.diet_experts = True
  hparams.layer_preprocess_sequence = "n"
  hparams.layer_postprocess_sequence = "da"
  hparams.layer_prepostprocess_dropout = 0.0
  hparams.memory_efficient_ffn = True
  hparams.attention_type = AttentionType.MEMORY_EFFICIENT
  hparams.num_heads = 8
  hparams.factored_logits = True
  return hparams