diff --git a/archai/algos/darts/bilevel_arch_trainer.py b/archai/algos/darts/bilevel_arch_trainer.py
index f81d1376..3ac7f902 100644
--- a/archai/algos/darts/bilevel_arch_trainer.py
+++ b/archai/algos/darts/bilevel_arch_trainer.py
@@ -15,7 +15,7 @@ from archai.nas.arch_trainer import ArchTrainer
 from archai.common import utils, ml_utils
 from archai.nas.model import Model
 from archai.common.checkpoint import CheckPoint
-from archai.common.common import logger, get_device
+from archai.common.common import logger
 from .bilevel_optimizer import BilevelOptimizer
 
 class BilevelArchTrainer(ArchTrainer):
@@ -36,10 +36,11 @@ class BilevelArchTrainer(ArchTrainer):
         assert val_dl is not None
         w_momentum = self._conf_w_optim['momentum']
         w_decay = self._conf_w_optim['decay']
-        lossfn = ml_utils.get_lossfn(self._conf_w_lossfn).to(get_device())
+        lossfn = ml_utils.get_lossfn(self._conf_w_lossfn).to(self.get_device())
 
         self._bilevel_optim = BilevelOptimizer(self._conf_alpha_optim, w_momentum,
-                                                w_decay, self.model, lossfn)
+                                                w_decay, self.model, lossfn,
+                                                self.get_device())
 
     @overrides
     def post_fit(self, train_dl:DataLoader, val_dl:Optional[DataLoader])->None:
@@ -71,7 +72,7 @@ class BilevelArchTrainer(ArchTrainer):
             self._valid_iter = iter(self._val_dl)
             x_val, y_val = next(self._valid_iter)
 
-        x_val, y_val = x_val.to(get_device()), y_val.to(get_device(), non_blocking=True)
+        x_val, y_val = x_val.to(self.get_device()), y_val.to(self.get_device(), non_blocking=True)
 
         # update alphas
         self._bilevel_optim.step(x, y, x_val, y_val, super().get_optimizer())
diff --git a/archai/algos/darts/bilevel_optimizer.py b/archai/algos/darts/bilevel_optimizer.py
index b9ede32e..fd0ea5a7 100644
--- a/archai/algos/darts/bilevel_optimizer.py
+++ b/archai/algos/darts/bilevel_optimizer.py
@@ -9,11 +9,11 @@ from torch.optim.optimizer import Optimizer
 from archai.common.config import Config
 from archai.common import utils, ml_utils
 from archai.nas.model import Model
-from archai.common.common import logger, get_device
+from archai.common.common import logger
 
 class BilevelOptimizer:
     def __init__(self, conf_alpha_optim:Config, w_momentum: float, w_decay: float,
-                 model: Model, lossfn: _Loss) -> None:
+                 model: Model, lossfn: _Loss, device) -> None:
         self._w_momentum = w_momentum  # momentum for w
         self._w_weight_decay = w_decay  # weight decay for w
         self._lossfn = lossfn
@@ -22,7 +22,7 @@ class BilevelOptimizer:
         # create a copy of model which we will use
         # to compute grads for alphas without disturbing
         # original weights
-        self._vmodel = copy.deepcopy(model).to(get_device())
+        self._vmodel = copy.deepcopy(model).to(device)
         # this is the optimizer to optimize alphas parameter
         self._alpha_optim = ml_utils.create_optimizer(conf_alpha_optim, model.alphas())
 
diff --git a/archai/algos/xnas/xnas_arch_trainer.py b/archai/algos/xnas/xnas_arch_trainer.py
index 5d2df886..e29e54bd 100644
--- a/archai/algos/xnas/xnas_arch_trainer.py
+++ b/archai/algos/xnas/xnas_arch_trainer.py
@@ -15,7 +15,7 @@ from archai.nas.arch_trainer import ArchTrainer
 from archai.common import utils, ml_utils
 from archai.nas.model import Model
 from archai.common.checkpoint import CheckPoint
-from archai.common.common import logger, get_device
+from archai.common.common import logger
 
 
 class XnasArchTrainer(ArchTrainer):
@@ -39,7 +39,7 @@ class XnasArchTrainer(ArchTrainer):
         # optimizers, schedulers needs to be recreated for each fit call
         # as they have state
         assert val_dl is not None
-        lossfn = ml_utils.get_lossfn(self._conf_w_lossfn).to(get_device())
+        lossfn = ml_utils.get_lossfn(self._conf_w_lossfn).to(self.get_device())
 
         self._xnas_optim = _XnasOptimizer(self._conf_alpha_optim, self.model, lossfn)
 
@@ -74,7 +74,7 @@ class XnasArchTrainer(ArchTrainer):
             self._valid_iter = iter(self._val_dl)
             x_val, y_val = next(self._valid_iter)
 
-        x_val, y_val = x_val.to(get_device()), y_val.to(get_device(), non_blocking=True)
+        x_val, y_val = x_val.to(self.get_device()), y_val.to(self.get_device(), non_blocking=True)
 
         # update alphas
         self._xnas_optim.step(x, y, x_val, y_val)
diff --git a/archai/common/apex_utils.py b/archai/common/apex_utils.py
index 32cd9a23..382e7e5c 100644
--- a/archai/common/apex_utils.py
+++ b/archai/common/apex_utils.py
@@ -15,23 +15,7 @@ from archai.common import ml_utils, utils
 from archai.common.ordereddict_logger import OrderedDictLogger
 
 class ApexUtils:
-    def __init__(self)->None:
-        self._amp = self._ddp = None
-        self._op_map = {'mean': dist.ReduceOp.SUM, 'sum': dist.ReduceOp.SUM,
-                    'min': dist.ReduceOp.MIN, 'max': dist.ReduceOp.MAX}
-        self.gpu_ids = [] # use all gpus
-
-        self._mixed_prec_enabled = False
-        self._distributed_enabled = False
-
-        self._set_ranks()
-
-    def reset(self, logger:OrderedDictLogger, apex_config:Config)->None:
-        # reset allows to configure differently for search or eval modes
-
-        # to avoid circular references= with common, logger is passed from outside
-        self.logger = logger
-
+    def __init__(self, apex_config:Config, logger:Optional[OrderedDictLogger])->None:
         # region conf vars
         self._enabled = apex_config['enabled'] # global switch to disable anything apex
         self._distributed_enabled = apex_config['distributed_enabled'] # enable/disable distributed mode
@@ -47,42 +31,53 @@ class ApexUtils:
         conf_gpu_ids = apex_config['gpus']
         # endregion
 
-        self.gpu_ids = [int(i) for i in conf_gpu_ids.split(',') if i]
-        self._amp, self._ddp = None, None
-        self._gpu = self.gpu_ids[0] if len(self.gpu_ids) else 0 # which GPU to use, we will use only 1 GPU
+        # to avoid circular references= with common, logger is passed from outside
+        self.logger = logger
 
-        #logger.info({'apex_config': apex_config.to_dict()})
-        logger.info({'torch.distributed.is_available': dist.is_available()})
+        self._op_map = {'mean': dist.ReduceOp.SUM, 'sum': dist.ReduceOp.SUM,
+                    'min': dist.ReduceOp.MIN, 'max': dist.ReduceOp.MAX}
+
+        # defaults for non-distributed mode
+        self._amp, self._ddp = None, None
+        self.world_size = 1
+        self.local_rank = self.global_rank = 0
+
+        self.gpu_ids = [int(i) for i in conf_gpu_ids.split(',') if i]
+
+        # which GPU to use, we will use only 1 GPU per process to avoid complications with apex
+        self._gpu = self.gpu_ids[0] if len(self.gpu_ids) else 0
+
+        #_log_info({'apex_config': apex_config.to_dict()})
+        self._log_info({'torch.distributed.is_available': dist.is_available()})
         if dist.is_available():
-            logger.info({'gloo_available': dist.is_gloo_available(),
+            self._log_info({'gloo_available': dist.is_gloo_available(),
                         'mpi_available': dist.is_mpi_available(),
                         'nccl_available': dist.is_nccl_available()})
 
-        if self._enabled:
-            if self._mixed_prec_enabled:
-                # init enable mixed precision
-                assert cudnn.enabled, "Amp requires cudnn backend to be enabled."
-                from apex import amp
-                self._amp = amp
+        if self.is_mixed():
+            # init enable mixed precision
+            assert cudnn.enabled, "Amp requires cudnn backend to be enabled."
+            from apex import amp
+            self._amp = amp
 
-            # enable distributed processing
-            if self._distributed_enabled:
-                from apex import parallel
-                self._ddp = parallel
+        # enable distributed processing
+        if self.is_dist():
+            from apex import parallel
+            self._ddp = parallel
 
-                assert dist.is_available() # distributed module is available
-                assert dist.is_nccl_available()
-                if not dist.is_initialized():
-                    dist.init_process_group(backend='nccl', init_method='env://')
-                    assert dist.is_initialized()
+            assert dist.is_available() # distributed module is available
+            assert dist.is_nccl_available()
+            if not dist.is_initialized():
+                dist.init_process_group(backend='nccl', init_method='env://')
+                assert dist.is_initialized()
 
-                self._set_ranks()
-                assert dist.get_world_size() == self.world_size
-                assert dist.get_rank() == self.global_rank
-            else:
-                assert self.world_size == 1
-                assert self.local_rank == 0
-                assert self.global_rank == 0
+            self._set_ranks()
+            assert dist.get_world_size() == self.world_size
+            assert dist.get_rank() == self.global_rank
+        else:
+            assert self.world_size == 1
+            assert self.local_rank == 0
+            assert self.global_rank == 0
 
         assert self.world_size >= 1
         assert not self._min_world_size or self.world_size >= self._min_world_size
@@ -94,9 +89,9 @@ class ApexUtils:
         self.device = torch.device('cuda', self._gpu)
         self._setup_gpus(seed, detect_anomaly)
 
-        logger.info({'amp_available': self._amp is not None,
+        self._log_info({'amp_available': self._amp is not None,
                      'distributed_available': self._ddp is not None})
-        logger.info({'dist_initialized': dist.is_initialized() if dist.is_available() else False,
+        self._log_info({'dist_initialized': dist.is_initialized() if dist.is_available() else False,
                      'world_size': self.world_size,
                      'gpu': self._gpu, 'gpu_ids':self.gpu_ids,
                      'local_rank': self.local_rank})
@@ -106,10 +101,10 @@ class ApexUtils:
         utils.setup_cuda(seed, self.local_rank)
 
         torch.autograd.set_detect_anomaly(detect_anomaly)
-        self.logger.info({'set_detect_anomaly': detect_anomaly,
+        self._log_info({'set_detect_anomaly': detect_anomaly,
                           'is_anomaly_enabled': torch.is_anomaly_enabled()})
 
-        self.logger.info({'gpu_names': utils.cuda_device_names(),
+        self._log_info({'gpu_names': utils.cuda_device_names(),
                     'gpu_count': torch.cuda.device_count(),
                     'CUDA_VISIBLE_DEVICES': os.environ['CUDA_VISIBLE_DEVICES']
                         if 'CUDA_VISIBLE_DEVICES' in os.environ else 'NotSet',
@@ -118,8 +113,8 @@ class ApexUtils:
                     'cudnn.deterministic': cudnn.deterministic,
                     'cudnn.version': cudnn.version()
                     })
-        self.logger.info({'memory': str(psutil.virtual_memory())})
-        self.logger.info({'CPUs': str(psutil.cpu_count())})
+        self._log_info({'memory': str(psutil.virtual_memory())})
+        self._log_info({'CPUs': str(psutil.cpu_count())})
 
         # gpu_usage = os.popen(
         #     'nvidia-smi --query-gpu=memory.total,memory.used --format=csv,nounits,noheader'
@@ -127,7 +122,7 @@ class ApexUtils:
         # for i, line in enumerate(gpu_usage):
         #     vals = line.split(',')
         #     if len(vals) == 2:
-        #         logger.info('GPU {} mem: {}, used: {}'.format(i, vals[0], vals[1]))
+        #         _log_info('GPU {} mem: {}, used: {}'.format(i, vals[0], vals[1]))
 
     def _set_ranks(self)->None:
         if 'WORLD_SIZE' in os.environ:
@@ -153,18 +148,22 @@ class ApexUtils:
             self._gpu = self.gpu_ids[self.local_rank]
 
     def is_mixed(self)->bool:
-        return self._mixed_prec_enabled
+        return self._enabled and self._mixed_prec_enabled
     def is_dist(self)->bool:
-        return self._distributed_enabled
+        return self._enabled and self._distributed_enabled
     def is_master(self)->bool:
         return self.global_rank == 0
 
+    def _log_info(self, d:dict)->None:
+        if self.logger is not None:
+            self.logger.info(d)
+
     def sync_devices(self)->None:
-        if self._distributed_enabled:
+        if self.is_dist():
             torch.cuda.synchronize(self.device)
 
     def reduce(self, val, op='mean'):
-        if self._distributed_enabled:
+        if self.is_dist():
             if not isinstance(val, Tensor):
                 rt = torch.tensor(val).to(self.device)
                 converted = True
@@ -184,7 +183,7 @@ class ApexUtils:
             return val
 
     def backward(self, loss:torch.Tensor, optim:Optimizer)->None:
-        if self._mixed_prec_enabled:
+        if self.is_mixed():
             with self._amp.scale_loss(loss, optim) as scaled_loss:
                 scaled_loss.backward()
         else:
@@ -193,26 +192,26 @@ class ApexUtils:
     def to_amp(self, model:nn.Module, optim:Optimizer, batch_size:int)\
                 ->Tuple[nn.Module, Optimizer]:
         # conver BNs to sync BNs in distributed mode
-        if self._distributed_enabled and self._sync_bn:
+        if self.is_dist() and self._sync_bn:
             model = self._ddp.convert_syncbn_model(model)
-            self.logger.info({'BNs_converted': True})
+            self._log_info({'BNs_converted': True})
 
         model = model.to(self.device)
 
-        if self._mixed_prec_enabled:
+        if self.is_mixed():
             # scale LR
             if self._scale_lr:
                 lr = ml_utils.get_optim_lr(optim)
                 scaled_lr = lr * self.world_size / float(batch_size)
                 ml_utils.set_optim_lr(optim, scaled_lr)
-                self.logger.info({'lr_scaled': True, 'old_lr': lr, 'new_lr': scaled_lr})
+                self._log_info({'lr_scaled': True, 'old_lr': lr, 'new_lr': scaled_lr})
 
             model, optim = self._amp.initialize(
                 model, optim, opt_level=self._opt_level,
                 keep_batchnorm_fp32=self._bn_fp32, loss_scale=self._loss_scale
             )
 
-        if self._distributed_enabled:
+        if self.is_dist():
             # By default, apex.parallel.DistributedDataParallel overlaps communication with
             # computation in the backward pass.
             # delay_allreduce delays all communication to the end of the backward pass.
@@ -222,19 +221,19 @@ class ApexUtils:
 
     def clip_grad(self, clip:float, model:nn.Module, optim:Optimizer)->None:
         if clip > 0.0:
-            if self._mixed_prec_enabled:
+            if self.is_mixed():
                 nn.utils.clip_grad_norm_(self._amp.master_params(optim), clip)
             else:
                 nn.utils.clip_grad_norm_(model.parameters(), clip)
 
     def state_dict(self):
-        if self._mixed_prec_enabled:
+        if self.is_mixed():
             return self._amp.state_dict()
         else:
             return None
 
     def load_state_dict(self, state_dict):
-        if self._mixed_prec_enabled:
+        if self.is_mixed():
             self._amp.load_state_dict()
 
 
diff --git a/archai/common/common.py b/archai/common/common.py
index f5ba331d..8d70d9fc 100644
--- a/archai/common/common.py
+++ b/archai/common/common.py
@@ -30,42 +30,11 @@ class SummaryWriterDummy:
 SummaryWriterAny = Union[SummaryWriterDummy, SummaryWriter]
 logger = OrderedDictLogger(None, None)
 _tb_writer: SummaryWriterAny = None
-_apex_utils = ApexUtils()
 _atexit_reg = False # is hook for atexit registered?
 
 def get_conf()->Config:
     return Config.get()
 
-def get_device():
-    global _apex_utils
-    return _apex_utils.device
-
-def get_apex_utils()->ApexUtils:
-    global _apex_utils
-    assert _apex_utils
-    return _apex_utils
-
-def is_dist()->bool:
-    global _apex_utils
-    return _apex_utils.is_dist()
-
-def reduce_min(val):
-    global _apex_utils
-    return _apex_utils.reduce(val, op='min')
-def reduce_max(val):
-    global _apex_utils
-    return _apex_utils.reduce(val, op='max')
-def reduce_sum(val):
-    global _apex_utils
-    return _apex_utils.reduce(val, op='sum')
-def reduce_mean(val):
-    global _apex_utils
-    return _apex_utils.reduce(val, op='mean')
-
-def is_dist()->bool:
-    global _apex_utils
-    return _apex_utils.is_dist()
-
 def get_conf_common()->Config:
     return get_conf()['common']
 
@@ -138,14 +107,18 @@ def common_init(config_filepath: Optional[str]=None,
     logger.info({'expdir': expdir,
                  'PT_DATA_DIR': pt_data_dir, 'PT_OUTPUT_DIR': pt_output_dir})
 
+    # create a[ex to know distributed processing paramters
+    conf_apex = get_conf_common()['apex']
+    apex = ApexUtils(conf_apex, None)
+
     # create global logger
-    _setup_logger()
+    _setup_logger(apex)
     # create info file for current system
     _create_sysinfo(conf)
 
     # setup tensorboard
     global _tb_writer
-    _tb_writer = _create_tb_writer(get_apex_utils().is_master())
+    _tb_writer = _create_tb_writer(apex.is_master())
 
     # create hooks to execute code when script exits
     global _atexit_reg
@@ -216,17 +189,18 @@ def _setup_dirs()->Optional[str]:
     os.environ['distdir'] = conf_common['distdir'] = distdir
 
 
-def _setup_logger():
+def _setup_logger(apex:ApexUtils):
     global logger
     logger.close()  # close any previous instances
 
     conf_common = get_conf_common()
     expdir = conf_common['expdir']
     distdir = conf_common['distdir']
-    global_rank = get_apex_utils().global_rank
+
+    global_rank = apex.global_rank
 
     # file where logger would log messages
-    if get_apex_utils().is_master():
+    if apex.is_master():
         sys_log_filepath = utils.full_path(os.path.join(expdir, 'logs.log'))
         logs_yaml_filepath = utils.full_path(os.path.join(expdir, 'logs.yaml'))
         experiment_name = get_experiment_name()
diff --git a/archai/common/metrics.py b/archai/common/metrics.py
index 712e1988..75bca302 100644
--- a/archai/common/metrics.py
+++ b/archai/common/metrics.py
@@ -11,7 +11,8 @@ from torch import Tensor
 import yaml
 
 from . import utils, ml_utils
-from .common import logger, get_tb_writer, is_dist, reduce_mean, reduce_sum, reduce_min, reduce_max
+from .common import logger, get_tb_writer
+from .apex_utils import ApexUtils
 
 
 class Metrics:
@@ -29,7 +30,7 @@ class Metrics:
     best we have seen for each epoch.
     """
 
-    def __init__(self, title:str, logger_freq:int=50) -> None:
+    def __init__(self, title:str, apex:Optional[ApexUtils], logger_freq:int=50) -> None:
         """Create the metrics object to maintain epoch stats
 
         Arguments:
@@ -39,6 +40,7 @@ class Metrics:
         """
         self.logger_freq = logger_freq
         self.title = title
+        self._apex = apex
         self._reset_run()
 
     def _reset_run(self)->None:
@@ -59,27 +61,27 @@ class Metrics:
                 logger.info({'epoch':self.run_metrics.epoch_time_avg(),
                             'step': self.run_metrics.step_time_avg(),
                             'run': self.run_metrics.duration()})
-                if is_dist():
-                    logger.info({'dist_epoch_sum': reduce_sum(self.run_metrics.epoch_time_avg()),
-                                'dist_step': reduce_mean(self.run_metrics.step_time_avg()),
-                                'dist_run_sum': reduce_sum(self.run_metrics.duration())})
+                if self.is_dist():
+                    logger.info({'dist_epoch_sum': self.reduce_sum(self.run_metrics.epoch_time_avg()),
+                                'dist_step': self.reduce_mean(self.run_metrics.step_time_avg()),
+                                'dist_run_sum': self.reduce_sum(self.run_metrics.duration())})
 
 
             best_train, best_val = self.run_metrics.best_epoch()
             with logger.pushd('best_train'):
                 logger.info({'epoch': best_train.index,
                             'top1': best_train.top1.avg})
-                if is_dist():
-                    logger.info({'dist_epoch': reduce_mean(best_train.index),
-                                'dist_top1': reduce_mean(best_train.top1.avg)})
+                if self.is_dist():
+                    logger.info({'dist_epoch': self.reduce_mean(best_train.index),
+                                'dist_top1': self.reduce_mean(best_train.top1.avg)})
 
             if best_val:
                 with logger.pushd('best_val'):
                     logger.info({'epoch': best_val.index,
                                 'top1': best_val.val_metrics.top1.avg})
-                    if is_dist():
-                        logger.info({'dist_epoch': reduce_mean(best_val.index),
-                                    'dist_top1': reduce_mean(best_val.val_metrics.top1.avg)})
+                    if self.is_dist():
+                        logger.info({'dist_epoch': self.reduce_mean(best_val.index),
+                                    'dist_top1': self.reduce_mean(best_val.val_metrics.top1.avg)})
 
     def pre_step(self, x: Tensor, y: Tensor):
         self.run_metrics.cur_epoch().pre_step()
@@ -102,11 +104,11 @@ class Metrics:
                         'loss': epoch.loss.avg,
                         'step_time': epoch.step_time.last})
 
-            if is_dist():
-                logger.info({'dist_top1': reduce_mean(epoch.top1.avg),
-                            'dist_top5': reduce_mean(epoch.top5.avg),
-                            'dist_loss': reduce_mean(epoch.loss.avg),
-                            'dist_step_time': reduce_mean(epoch.step_time.last)})
+            if self.is_dist():
+                logger.info({'dist_top1': self.reduce_mean(epoch.top1.avg),
+                            'dist_top5': self.reduce_mean(epoch.top5.avg),
+                            'dist_loss': self.reduce_mean(epoch.loss.avg),
+                            'dist_step_time': self.reduce_mean(epoch.step_time.last)})
 
 
         # NOTE: Tensorboard step-level logging is removed as it becomes exponentially expensive on Azure blobs
@@ -143,24 +145,24 @@ class Metrics:
                             'duration': epoch.duration(),
                             'step_time': epoch.step_time.avg,
                             'end_lr': lr})
-                if is_dist():
-                    logger.info({'dist_top1': reduce_mean(epoch.top1.avg),
-                                'dist_top5': reduce_mean(epoch.top5.avg),
-                                'dist_loss': reduce_mean(epoch.loss.avg),
-                                'dist_duration': reduce_mean(epoch.duration()),
-                                'dist_step_time': reduce_mean(epoch.step_time.avg),
-                                'dist_end_lr': reduce_mean(lr)})
+                if self.is_dist():
+                    logger.info({'dist_top1': self.reduce_mean(epoch.top1.avg),
+                                'dist_top5': self.reduce_mean(epoch.top5.avg),
+                                'dist_loss': self.reduce_mean(epoch.loss.avg),
+                                'dist_duration': self.reduce_mean(epoch.duration()),
+                                'dist_step_time': self.reduce_mean(epoch.step_time.avg),
+                                'dist_end_lr': self.reduce_mean(lr)})
             if test_epoch:
                 with logger.pushd('val'):
                     logger.info({'top1': test_epoch.top1.avg,
                                 'top5': test_epoch.top5.avg,
                                 'loss': test_epoch.loss.avg,
                                 'duration': epoch.duration()})
-                    if is_dist():
-                        logger.info({'dist_top1': reduce_mean(test_epoch.top1.avg),
-                                    'dist_top5': reduce_mean(test_epoch.top5.avg),
-                                    'dist_loss': reduce_mean(test_epoch.loss.avg),
-                                    'dist_duration': reduce_mean(test_epoch.duration())})
+                    if self.is_dist():
+                        logger.info({'dist_top1': self.reduce_mean(test_epoch.top1.avg),
+                                    'dist_top5': self.reduce_mean(test_epoch.top5.avg),
+                                    'dist_loss': self.reduce_mean(test_epoch.loss.avg),
+                                    'dist_duration': self.reduce_mean(test_epoch.duration())})
 
         # writer = get_tb_writer()
         # writer.add_scalar(f'{self._tb_path}/train_epochs/loss',
@@ -181,9 +183,14 @@ class Metrics:
         return utils.state_dict(self)
 
     def load_state_dict(self, state_dict:dict)->None:
-        # simply convert current object to dictionary
         utils.load_state_dict(self, state_dict)
 
+    def __getstate__(self):
+        state = self.__dict__.copy()
+        del state['_apex'] # cannot serialize this
+        return state
+    # no need to define __setstate__ because _apex should be set from constructor
+
     def save(self, filepath:str)->Optional[str]:
         if filepath:
             filepath = utils.full_path(filepath)
@@ -197,6 +204,27 @@ class Metrics:
     def cur_epoch(self)->'EpochMetrics':
         return self.run_metrics.cur_epoch()
 
+    def reduce_min(self, val):
+        if not self._apex:
+            return val
+        return self._apex.reduce(val, op='min')
+    def reduce_max(self, val):
+        if not self._apex:
+            return val
+        return self._apex.reduce(val, op='max')
+    def reduce_sum(self, val):
+        if not self._apex:
+            return val
+        return self._apex.reduce(val, op='sum')
+    def reduce_mean(self, val):
+        if not self._apex:
+            return val
+        return self._apex.reduce(val, op='mean')
+    def is_dist(self)->bool:
+        if not self._apex:
+            return False
+        return self._apex.is_dist()
+
 
 class Accumulator:
     # TODO: replace this with Metrics class
diff --git a/archai/common/tester.py b/archai/common/tester.py
index afd7b3be..4afb93b8 100644
--- a/archai/common/tester.py
+++ b/archai/common/tester.py
@@ -9,18 +9,18 @@ from overrides import EnforceOverrides
 from .metrics import Metrics
 from .config import Config
 from . import utils, ml_utils
-from .common import logger, get_device
-from archai.common.common import get_apex_utils
+from .common import logger
+from archai.common.apex_utils import ApexUtils
 
 class Tester(EnforceOverrides):
-    def __init__(self, conf_eval:Config, model:nn.Module)->None:
-        # TODO: currently we expect that given model and dataloader will already be distributed
+    def __init__(self, conf_eval:Config, model:nn.Module, apex:ApexUtils)->None:
         self._title = conf_eval['title']
         self._logger_freq = conf_eval['logger_freq']
         conf_lossfn = conf_eval['lossfn']
 
+        self._apex = apex
         self.model = model
-        self._lossfn = ml_utils.get_lossfn(conf_lossfn).to(get_device())
+        self._lossfn = ml_utils.get_lossfn(conf_lossfn).to(apex.device)
         self._metrics = None
 
     def test(self, test_dl: DataLoader)->Metrics:
@@ -43,7 +43,7 @@ class Tester(EnforceOverrides):
 
         with torch.no_grad(), logger.pushd('steps'):
             for step, (x, y) in enumerate(test_dl):
-                x, y = x.to(get_device(), non_blocking=True), y.to(get_device(), non_blocking=True)
+                x, y = x.to(self._apex.device, non_blocking=True), y.to(self._apex.device, non_blocking=True)
 
                 assert not self.model.training # derived class might alter the mode
                 logger.pushd(step)
@@ -57,7 +57,7 @@ class Tester(EnforceOverrides):
                 self._post_step(x, y, logits, loss, steps, self._metrics)
 
                 # TODO: we possibly need to sync so all replicas are upto date
-                get_apex_utils().sync_devices()
+                self._apex.sync_devices()
 
                 logger.popd()
         self._metrics.post_epoch(None)
@@ -87,5 +87,5 @@ class Tester(EnforceOverrides):
         metrics.post_step(x, y, logits, loss, steps)
 
     def _create_metrics(self)->Metrics:
-        return Metrics(self._title, logger_freq=self._logger_freq)
+        return Metrics(self._title, self._apex, logger_freq=self._logger_freq)
 
diff --git a/archai/common/trainer.py b/archai/common/trainer.py
index 10a52d7f..98ea4091 100644
--- a/archai/common/trainer.py
+++ b/archai/common/trainer.py
@@ -11,8 +11,9 @@ from .metrics import Metrics
 from .tester import Tester
 from .config import Config
 from . import utils, ml_utils
-from ..common.common import logger, get_device, get_apex_utils
+from ..common.common import logger
 from ..common.checkpoint import CheckPoint
+from ..common.apex_utils import ApexUtils
 
 
 class Trainer(EnforceOverrides):
@@ -33,13 +34,13 @@ class Trainer(EnforceOverrides):
         self._validation_freq = 0 if conf_validation is None else conf_validation['freq']
         # endregion
 
-        get_apex_utils().reset(logger, conf_apex)
+        self._apex = ApexUtils(conf_apex, logger)
 
         self._checkpoint = checkpoint
         self.model = model
 
         self._lossfn = ml_utils.get_lossfn(conf_lossfn)
-        self._tester = Tester(conf_validation, model) \
+        self._tester = Tester(conf_validation, model, self._apex) \
                         if conf_validation else None
         self._metrics:Optional[Metrics] = None
 
@@ -52,7 +53,7 @@ class Trainer(EnforceOverrides):
     def fit(self, train_dl:DataLoader, val_dl:Optional[DataLoader])->Metrics:
         logger.pushd(self._title)
 
-        self._metrics = Metrics(self._title, logger_freq=self._logger_freq)
+        self._metrics = Metrics(self._title, self._apex, logger_freq=self._logger_freq)
 
         # optimizers, schedulers needs to be recreated for each fit call
         # as they have state specific to each run
@@ -60,10 +61,10 @@ class Trainer(EnforceOverrides):
         # create scheduler for optim before applying amp
         self._sched, self._sched_on_epoch = self._create_scheduler(optim, len(train_dl))
         # before checkpoint restore, convert to amp
-        self.model, self._optim = get_apex_utils().to_amp(self.model, optim,
+        self.model, self._optim = self._apex.to_amp(self.model, optim,
                                                           batch_size=train_dl.batch_size)
 
-        self._lossfn = self._lossfn.to(get_device())
+        self._lossfn = self._lossfn.to(self.get_device())
 
         self.pre_fit(train_dl, val_dl)
 
@@ -158,7 +159,7 @@ class Trainer(EnforceOverrides):
         self._metrics.post_epoch(val_metrics, lr=self._optim.param_groups[0]['lr'])
 
         # checkpoint if enabled with given freq or if this is the last epoch
-        if self._checkpoint is not None and get_apex_utils().is_master() and \
+        if self._checkpoint is not None and self._apex.is_master() and \
             self._checkpoint.freq > 0 and (self._metrics.epochs() % self._checkpoint.freq == 0 or \
                     self._metrics.epochs() >= self._epochs):
             self._checkpoint.new()
@@ -173,6 +174,9 @@ class Trainer(EnforceOverrides):
         self._metrics.post_step(x, y, logits, loss, steps)
     #########################  hooks #########################
 
+    def get_device(self):
+        return self._apex.device
+
     def restore_checkpoint(self)->None:
         state = self._checkpoint['trainer']
         last_epoch = state['last_epoch']
@@ -180,7 +184,7 @@ class Trainer(EnforceOverrides):
 
         self._metrics.load_state_dict(state['metrics'])
         assert self._metrics.epochs() == last_epoch+1
-        get_apex_utils().load_state_dict(state['amp'])
+        self._apex.load_state_dict(state['amp'])
         self.model.load_state_dict(state['model'])
         self._optim.load_state_dict(state['optim'])
         if self._sched:
@@ -198,7 +202,7 @@ class Trainer(EnforceOverrides):
             'model': self.model.state_dict(),
             'optim': self._optim.state_dict(),
             'sched': self._sched.state_dict() if self._sched else None,
-            'amp': get_apex_utils().state_dict()
+            'amp': self._apex.state_dict()
         }
         self._checkpoint['trainer'] = state
 
@@ -208,7 +212,7 @@ class Trainer(EnforceOverrides):
 
         logger.pushd('steps')
         for step, (x, y) in enumerate(train_dl):
-            x, y = x.to(get_device(), non_blocking=True), y.to(get_device(), non_blocking=True)
+            x, y = x.to(self.get_device(), non_blocking=True), y.to(self.get_device(), non_blocking=True)
 
             logger.pushd(step)
             assert self.model.training # derived class might alter the mode
@@ -226,15 +230,15 @@ class Trainer(EnforceOverrides):
             loss = self.compute_loss(self._lossfn, x, y, logits,
                                     self._aux_weight, aux_logits)
 
-            get_apex_utils().backward(loss, self._optim)
+            self._apex.backward(loss, self._optim)
 
             # TODO: original darts clips alphas as well but pt.darts doesn't
-            get_apex_utils().clip_grad(self._grad_clip, self.model, self._optim)
+            self._apex.clip_grad(self._grad_clip, self.model, self._optim)
 
             self._optim.step()
 
             # TODO: we possibly need to sync so all replicas are upto date
-            get_apex_utils().sync_devices()
+            self._apex.sync_devices()
 
             if self._sched and not self._sched_on_epoch:
                 self._sched.step()
diff --git a/archai/common/utils.py b/archai/common/utils.py
index 5582255d..58f8694e 100644
--- a/archai/common/utils.py
+++ b/archai/common/utils.py
@@ -55,7 +55,7 @@ def deep_update(d:MutableMapping, u:Mapping, map_type:Type[MutableMapping]=dict)
     return d
 
 def state_dict(val)->Mapping:
-    assert hasattr(val, '__dict__'), 'val must be object with __dict__'
+    assert hasattr(val, '__dict__'), 'val must be object with __dict__ otherwise it cannot be loaded back in load_state_dict'
 
     # Can't do below because val has state_dict() which calls utils.state_dict
     # if has_method(val, 'state_dict'):
@@ -76,8 +76,8 @@ def load_state_dict(val:Any, state_dict:Mapping)->None:
     assert s is not None, 'state_dict must contain yaml key'
 
     obj = yaml.load(s, Loader=yaml.Loader)
-    for k in val.__dict__.keys():
-        setattr(val, k, getattr(obj, k))
+    for k, v in obj.__dict__.items():
+        setattr(val, k, v)
 
 def deep_comp(o1:Any, o2:Any)->bool:
     # NOTE: dict don't have __dict__
diff --git a/confs/algos/darts.yaml b/confs/algos/darts.yaml
index 79e8491c..93fbbecd 100644
--- a/confs/algos/darts.yaml
+++ b/confs/algos/darts.yaml
@@ -19,8 +19,8 @@ common:
   redis: null
   apex: # this is overriden in search and eval individually
     enabled: False # global switch to disable anything apex
-    distributed_enabled: False # enable/disable distributed mode
-    mixed_prec_enabled: False # switch to disable amp mixed precision
+    distributed_enabled: True # enable/disable distributed mode
+    mixed_prec_enabled: True # switch to disable amp mixed precision
     gpus: '' # use GPU IDs specified here (comma separated), if '' then use all GPUs
     opt_level: 'O2' # optimization level for mixed precision
     bn_fp32: True # keep BN in fp32
@@ -88,6 +88,7 @@ nas:
     trainer:
       apex:
         _copy: 'common/apex'
+        enabled: True
       aux_weight: '_copy: nas/eval/model_desc/aux_weight'
       drop_path_prob: 0.2 # probability that given edge will be dropped
       grad_clip: 5.0 # grads above this value is clipped
diff --git a/scripts/misc/yaml_playground.py b/scripts/misc/yaml_playground.py
index 15ce4862..eed50f37 100644
--- a/scripts/misc/yaml_playground.py
+++ b/scripts/misc/yaml_playground.py
@@ -1,10 +1,27 @@
+from collections import UserDict
 import yaml
+from typing import Iterator
 
-y = """
-a: .NaN
+class A(object):
+    def __init__(self):
+        self.hidden = 42
+        self.visible = 5
 
-"""
+    def __getstate__(self):
+        state = self.__dict__.copy()
+        del state['hidden'] # cannot serialize this
+        return state
 
-d=yaml.load(y, Loader=yaml.Loader)
+a = A()
+d = yaml.dump(a)
 print(d)
-print(type( d['a']))
+
+
+# y = """
+# a: .NaN
+
+# """
+
+# d=yaml.load(y, Loader=yaml.Loader)
+# print(d)
+# print(type( d['a']))
diff --git a/scripts/perf/resnet_test.py b/scripts/perf/resnet_test.py
index 34b3d1a2..a9a36791 100644
--- a/scripts/perf/resnet_test.py
+++ b/scripts/perf/resnet_test.py
@@ -5,7 +5,7 @@ from archai import cifar10_models
 
 from archai.common.trainer import Trainer
 from archai.common.config import Config
-from archai.common.common import logger, common_init, get_device
+from archai.common.common import logger, common_init
 from archai.datasets import data
 
 def train_test(conf_eval:Config):
@@ -24,7 +24,7 @@ def train_test(conf_eval:Config):
     conf_trainer['aux_weight'] = 0.0
 
     Net = cifar10_models.resnet34
-    model = Net().to(get_device())
+    model = Net().to(torch.device('cuda', 0))
 
     # get data
     train_dl, _, test_dl = data.get_data(conf_loader)