diff --git a/launch.py b/launch.py
index 5c8d305e..b5a77fb9 100644
--- a/launch.py
+++ b/launch.py
@@ -1,3 +1,4 @@
+import sys
 import argparse
 import os
 import time
@@ -87,13 +88,20 @@ def main():
             TensorBoardLogger(args.runs_dir, name=config.name, version=config.trial_name),
             CSVLogger(config.exp_dir, name=config.trial_name, version='csv_logs')
         ]
-
+    
+    if sys.platform == 'win32':
+        # does not support multi-gpu on windows
+        strategy = 'dp'
+        assert n_gpus == 1
+    else:
+        strategy = 'ddp_find_unused_parameters_false'
+    
     trainer = Trainer(
         devices=n_gpus,
         accelerator='gpu',
         callbacks=callbacks,
         logger=loggers,
-        strategy='ddp_find_unused_parameters_false',
+        strategy=strategy,
         **config.trainer
     )
 
diff --git a/models/network_utils.py b/models/network_utils.py
index 38b70453..f5bafbbf 100644
--- a/models/network_utils.py
+++ b/models/network_utils.py
@@ -8,6 +8,7 @@
 from pytorch_lightning.utilities.rank_zero import rank_zero_debug, _get_rank
 
 from utils.misc import config_to_primitive
+from models.utils import get_activation
 
 
 
@@ -69,9 +70,12 @@ def __init__(self, dim_in, dim_out, config):
             self.layers += [self.make_linear(self.n_neurons, self.n_neurons, is_first=False, is_last=False), self.make_activation()]
         self.layers += [self.make_linear(self.n_neurons, dim_out, is_first=False, is_last=True)]
         self.layers = nn.Sequential(*self.layers)
+        self.output_activation = get_activation(config['output_activation'])
     
     def forward(self, x):
-        return self.layers(x.float())
+        x = self.layers(x.float())
+        x = self.output_activation(x)
+        return x
     
     def make_linear(self, dim_in, dim_out, is_first, is_last):
         layer = nn.Linear(dim_in, dim_out, bias=False)
diff --git a/models/utils.py b/models/utils.py
index 3918bd60..5dacbf65 100644
--- a/models/utils.py
+++ b/models/utils.py
@@ -67,7 +67,8 @@ def backward(ctx, g):  # pylint: disable=arguments-differ
 
 
 def get_activation(name):
-    if name is None or name in ['none', 'None']:
+    name = name.lower()
+    if name is None or name == 'none':
         return nn.Identity()
     elif name.startswith('scale'):
         scale_factor = float(name[5:])
diff --git a/systems/nerf.py b/systems/nerf.py
index 61a10a06..44a81274 100644
--- a/systems/nerf.py
+++ b/systems/nerf.py
@@ -152,8 +152,13 @@ def validation_epoch_end(self, out):
         if self.trainer.is_global_zero:
             out_set = {}
             for step_out in out:
-                for oi, index in enumerate(step_out['index']):
-                    out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
+                # DP
+                if step_out['index'].ndim == 1:
+                    out_set[step_out['index'].item()] = {'psnr': step_out['psnr']}
+                # DDP
+                else:
+                    for oi, index in enumerate(step_out['index']):
+                        out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
             psnr = torch.mean(torch.stack([o['psnr'] for o in out_set.values()]))
             self.log('val/psnr', psnr, prog_bar=True, rank_zero_only=True)         
 
@@ -180,8 +185,13 @@ def test_epoch_end(self, out):
         if self.trainer.is_global_zero:
             out_set = {}
             for step_out in out:
-                for oi, index in enumerate(step_out['index']):
-                    out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
+                # DP
+                if step_out['index'].ndim == 1:
+                    out_set[step_out['index'].item()] = {'psnr': step_out['psnr']}
+                # DDP
+                else:
+                    for oi, index in enumerate(step_out['index']):
+                        out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
             psnr = torch.mean(torch.stack([o['psnr'] for o in out_set.values()]))
             self.log('test/psnr', psnr, prog_bar=True, rank_zero_only=True)    
 
diff --git a/systems/neus.py b/systems/neus.py
index 7bb2c268..a609c9ad 100644
--- a/systems/neus.py
+++ b/systems/neus.py
@@ -163,8 +163,13 @@ def validation_epoch_end(self, out):
         if self.trainer.is_global_zero:
             out_set = {}
             for step_out in out:
-                for oi, index in enumerate(step_out['index']):
-                    out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
+                # DP
+                if step_out['index'].ndim == 1:
+                    out_set[step_out['index'].item()] = {'psnr': step_out['psnr']}
+                # DDP
+                else:
+                    for oi, index in enumerate(step_out['index']):
+                        out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
             psnr = torch.mean(torch.stack([o['psnr'] for o in out_set.values()]))
             self.log('val/psnr', psnr, prog_bar=True, rank_zero_only=True)         
 
@@ -195,8 +200,13 @@ def test_epoch_end(self, out):
         if self.trainer.is_global_zero:
             out_set = {}
             for step_out in out:
-                for oi, index in enumerate(step_out['index']):
-                    out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
+                # DP
+                if step_out['index'].ndim == 1:
+                    out_set[step_out['index'].item()] = {'psnr': step_out['psnr']}
+                # DDP
+                else:
+                    for oi, index in enumerate(step_out['index']):
+                        out_set[index[0].item()] = {'psnr': step_out['psnr'][oi]}
             psnr = torch.mean(torch.stack([o['psnr'] for o in out_set.values()]))
             self.log('test/psnr', psnr, prog_bar=True, rank_zero_only=True)