unload depth model if medvram/lowvram enabled

    if hasattr(sd_model.cond_stage_model, 'model'):

        sd_model.cond_stage_model.transformer = sd_model.cond_stage_model.model

    # remove three big modules, cond, first_stage, and unet from the model and then

    # remove four big modules, cond, first_stage, depth (if applicable), and unet from the model and then

    # send the model to GPU. Then put modules back. the modules will be in CPU.

    stored = sd_model.cond_stage_model.transformer, sd_model.first_stage_model, sd_model.model

    sd_model.cond_stage_model.transformer, sd_model.first_stage_model, sd_model.model = None, None, None

    stored = sd_model.cond_stage_model.transformer, sd_model.first_stage_model, getattr(sd_model, 'depth_model', None), sd_model.model

    sd_model.cond_stage_model.transformer, sd_model.first_stage_model, sd_model.depth_model, sd_model.model = None, None, None, None

    sd_model.to(devices.device)

    sd_model.cond_stage_model.transformer, sd_model.first_stage_model, sd_model.model = stored

    sd_model.cond_stage_model.transformer, sd_model.first_stage_model, sd_model.depth_model, sd_model.model = stored

    # register hooks for those the first two models

    # register hooks for those the first three models

    sd_model.cond_stage_model.transformer.register_forward_pre_hook(send_me_to_gpu)

    sd_model.first_stage_model.register_forward_pre_hook(send_me_to_gpu)

    sd_model.first_stage_model.encode = first_stage_model_encode_wrap

    sd_model.first_stage_model.decode = first_stage_model_decode_wrap

    if sd_model.depth_model:

        sd_model.depth_model.register_forward_pre_hook(send_me_to_gpu)

    parents[sd_model.cond_stage_model.transformer] = sd_model.cond_stage_model

    if hasattr(sd_model.cond_stage_model, 'model'):