diff --git a/colossalai/engine/ophooks/zero_hook.py b/colossalai/engine/ophooks/zero_hook.py
index a43cf1878..4dfe924dd 100644
--- a/colossalai/engine/ophooks/zero_hook.py
+++ b/colossalai/engine/ophooks/zero_hook.py
@@ -30,7 +30,7 @@ class ZeroHook(BaseOpHook):
         self.process_group = process_group
 
         # NOTE(jiaruifang) Now the computing device of FWD and BWD is always on GPU
-        self.computing_device = torch.device(f'cuda:{get_current_device()}')
+        self.computing_device = get_current_device()
 
         self._memstarts_collector = memstarts_collector
         self._stateful_tensor_mgr = stateful_tensor_mgr
diff --git a/colossalai/utils/__init__.py b/colossalai/utils/__init__.py
index 5e46d215a..2fd5a7951 100644
--- a/colossalai/utils/__init__.py
+++ b/colossalai/utils/__init__.py
@@ -8,7 +8,7 @@ from .common import (clip_grad_norm_fp32, conditional_context, copy_tensor_paral
                      sync_model_param, disposable)
 from .data_sampler import DataParallelSampler, get_dataloader
 from .gradient_accumulation import accumulate_gradient
-from .memory_utils.memory_monitor import report_memory_usage
+from .memory import report_memory_usage, colo_device_memory_used, colo_set_process_memory_fraction, colo_device_memory_capacity
 from .timer import MultiTimer, Timer
 from .tensor_detector import TensorDetector
 
@@ -17,7 +17,8 @@ __all__ = [
     'is_no_pp_or_last_stage', 'is_using_ddp', 'is_using_pp', 'is_using_sequence', 'conditional_context',
     'is_model_parallel_parameter', 'clip_grad_norm_fp32', 'count_zeros_fp32', 'copy_tensor_parallel_attributes',
     'param_is_not_tensor_parallel_duplicate', 'get_current_device', 'synchronize', 'empty_cache', 'set_to_cuda',
-    'report_memory_usage', 'Timer', 'MultiTimer', 'multi_tensor_applier', 'accumulate_gradient', 'DataParallelSampler',
-    'get_dataloader', 'switch_virtual_pipeline_parallel_rank', 'TensorDetector', 'load_checkpoint', 'save_checkpoint',
+    'report_memory_usage', 'colo_device_memory_capacity', 'colo_device_memory_used', 'colo_set_process_memory_fraction',
+    'Timer', 'MultiTimer', 'multi_tensor_applier', 'accumulate_gradient', 'DataParallelSampler', 'get_dataloader',
+    'switch_virtual_pipeline_parallel_rank', 'TensorDetector', 'load_checkpoint', 'save_checkpoint',
     'ensure_path_exists', 'disposable'
 ]
diff --git a/colossalai/utils/cuda.py b/colossalai/utils/cuda.py
index b287fa276..60f3ccb60 100644
--- a/colossalai/utils/cuda.py
+++ b/colossalai/utils/cuda.py
@@ -20,13 +20,15 @@ def set_to_cuda(models):
         return models.to(get_current_device())
 
 
-def get_current_device():
-    """Returns the index of a currently selected device (gpu/cpu).
+def get_current_device() -> torch.device:
+    """
+    Returns currently selected device (gpu/cpu).
+    If cuda available, return gpu, otherwise return cpu.    
     """
     if torch.cuda.is_available():
-        return torch.cuda.current_device()
+        return torch.device(f'cuda:{torch.cuda.current_device()}')
     else:
-        return 'cpu'
+        return torch.device('cpu')
 
 
 def synchronize():
diff --git a/colossalai/utils/memory.py b/colossalai/utils/memory.py
new file mode 100644
index 000000000..799e68f4d
--- /dev/null
+++ b/colossalai/utils/memory.py
@@ -0,0 +1,147 @@
+import torch
+import gc
+import psutil
+from collections import namedtuple
+
+from colossalai.context.parallel_mode import ParallelMode
+from colossalai.utils import get_current_device
+from colossalai.core import global_context as gpc
+from colossalai.context.parallel_mode import ParallelMode
+from colossalai.logging import get_dist_logger
+
+_GLOBAL_CUDA_MEM_FRACTION = 1.0
+
+
+def _bytes_to_MB(val, decimal=2):
+    """A byte-to-Megabyte converter, default using binary notation.
+
+    :param val: X bytes to convert
+    :return: X' MB
+    """
+    return round(val / (1024 * 1024), decimal)
+
+
+# copy from PatrickStar
+def _get_cpu_memory_info():
+    ps_mem_info = namedtuple("ps_mem_info", ["total", "free", "cached", "buffers", "used"])
+    try:
+        # psutil reads the memory info from /proc/memory_info,
+        # which results in returning the host memory instead of
+        # that of container.
+        # Here we try to read the container memory with method in:
+        # https://stackoverflow.com/a/46213331/5163915
+        mems = {}
+        with open("/sys/fs/cgroup/memory/memory.meminfo", "rb") as f:
+            for line in f:
+                fields = line.split()
+                mems[fields[0]] = int(fields[1]) * 1024
+        total = mems[b"MemTotal:"]
+        free = mems[b"MemFree:"]
+        cached = mems[b"Cached:"]
+        buffers = mems[b"Buffers:"]
+        used = total - free - cached - buffers
+        if used < 0:
+            used = total - free
+        mem_info = ps_mem_info(total=total, free=free, cached=cached, buffers=buffers, used=used)
+    except FileNotFoundError:
+        mems = psutil.virtual_memory()
+        mem_info = ps_mem_info(
+            total=mems.total,
+            free=mems.free,
+            cached=mems.cached,
+            buffers=mems.buffers,
+            used=mems.used,
+        )
+    return mem_info
+
+
+def report_memory_usage(message, logger=None, report_cpu=False):
+    """Calculate and print RAM usage (in GB)
+
+    Args:
+        message (str): A prefix message to add in the log.
+        logger (:class:`colossalai.logging.DistributedLogger`): The logger used to record memory information.
+        report_cpu (bool, optional): Whether to report CPU memory.
+
+    Raises:
+        EnvironmentError: Raise error if no distributed environment has been initialized.
+    """
+    if not gpc.is_initialized(ParallelMode.GLOBAL):
+        raise EnvironmentError("No distributed environment is initialized")
+
+    gpu_allocated = _bytes_to_MB(torch.cuda.memory_allocated())
+    gpu_max_allocated = _bytes_to_MB(torch.cuda.max_memory_allocated())
+    gpu_cached = _bytes_to_MB(torch.cuda.memory_reserved())
+    gpu_max_cached = _bytes_to_MB(torch.cuda.max_memory_reserved())
+
+    full_log = f"{message}: GPU: allocated {gpu_allocated} MB, max allocated {gpu_max_allocated} MB, " \
+        + f"cached: {gpu_cached} MB, max cached: {gpu_max_cached} MB"
+
+    if report_cpu:
+        # python doesn't do real-time garbage collection so do it explicitly to get the correct RAM reports
+        gc.collect()
+        vm_stats = psutil.virtual_memory()
+        vm_used = _bytes_to_MB(vm_stats.total - vm_stats.available)
+        full_log += f", CPU Virtual Memory: used = {vm_used} MB, percent = {vm_stats.percent}%"
+
+    if logger is None:
+        logger = get_dist_logger()
+    logger.info(full_log)
+
+    # get the peak memory to report correct data, so reset the counter for the next call
+    if hasattr(torch.cuda, "reset_peak_memory_stats"):    # pytorch 1.4+
+        torch.cuda.reset_peak_memory_stats()
+
+
+def colo_device_memory_capacity(device: torch.device) -> int:
+    """
+    Get the capacity of the memory of the device
+
+    Args:
+        device (torch.device): a device
+
+    Returns:
+        int: size in byte
+    """
+    assert isinstance(device, torch.device)
+    if device.type == 'cpu':
+        mem_info = _get_cpu_memory_info()
+        return mem_info.info.total / gpc.get_world_size(ParallelMode.DATA)
+    if device.type == 'cuda':
+        return torch.cuda.get_device_properties(get_current_device()).total_memory * _GLOBAL_CUDA_MEM_FRACTION
+
+
+def colo_device_memory_used(device: torch.device) -> int:
+    """
+    Get the device memory on device belonging to the current process.
+
+    Args:
+        device (torch.device): a device
+
+    Returns:
+        int: memory size in bytes
+    """
+    if device.type == 'cpu':
+        mem_info = _get_cpu_memory_info()
+        # FIXME(jiaruifang) we need get how many processes are using the CPU memory.
+        ret = mem_info.used / gpc.get_world_size(ParallelMode.DATA)
+        return ret
+    elif device.type == 'cuda':
+        ret: int = torch.cuda.memory_allocated(device)
+        # get the peak memory to report correct data, so reset the counter for the next call
+        if hasattr(torch.cuda, "reset_peak_memory_stats"):    # pytorch 1.4+
+            torch.cuda.reset_peak_memory_stats(device)
+        return ret
+
+
+def colo_set_process_memory_fraction(ratio: float) -> None:
+    """colo_set_process_memory_fraction 
+
+    set how much cuda memory used on the gpu belonging to the current process.
+
+    Args:
+        ratio (float): a ratio between 0. ~ 1.
+    """
+    global _GLOBAL_CUDA_MEM_FRACTION
+    _GLOBAL_CUDA_MEM_FRACTION = ratio
+    torch.cuda.set_per_process_memory_fraction(_GLOBAL_CUDA_MEM_FRACTION, get_current_device())
diff --git a/colossalai/utils/memory_tracer/async_memtracer.py b/colossalai/utils/memory_tracer/async_memtracer.py
index 7ceaf9d80..3be66cd9c 100644
--- a/colossalai/utils/memory_tracer/async_memtracer.py
+++ b/colossalai/utils/memory_tracer/async_memtracer.py
@@ -4,7 +4,7 @@ import pickle
 
 import torch
 
-from colossalai.utils.memory_utils.utils import colo_device_memory_used
+from colossalai.utils.memory import colo_device_memory_used
 from colossalai.utils import get_current_device
 
 
diff --git a/colossalai/utils/memory_tracer/memstats_collector.py b/colossalai/utils/memory_tracer/memstats_collector.py
index 1c93998cc..5da971ab5 100644
--- a/colossalai/utils/memory_tracer/memstats_collector.py
+++ b/colossalai/utils/memory_tracer/memstats_collector.py
@@ -1,5 +1,5 @@
 from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
-from colossalai.utils.memory_utils.utils import colo_device_memory_used
+from colossalai.utils.memory import colo_device_memory_used
 from colossalai.utils.memory_tracer.async_memtracer import AsyncMemoryMonitor
 import torch
 import time
diff --git a/colossalai/utils/memory_utils/__init__.py b/colossalai/utils/memory_utils/__init__.py
deleted file mode 100644
index e69de29bb..000000000
diff --git a/colossalai/utils/memory_utils/bucket_tensor_copy.py b/colossalai/utils/memory_utils/bucket_tensor_copy.py
deleted file mode 100644
index f65a75a81..000000000
--- a/colossalai/utils/memory_utils/bucket_tensor_copy.py
+++ /dev/null
@@ -1,61 +0,0 @@
-import torch
-from colossalai.zero.sharded_param import ShardedParamV2
-from colossalai.utils import get_current_device
-from typing import List
-
-
-class BucketizedTensorCopy(object):
-
-    def __init__(
-        self,
-        chunk_size: int,
-    ):
-        r""" 
-        torch.nn.Parameter CPU (fp32) -> ShardedParam GPU (fp16)
-        TODO(jiaruifang) The class is a little bit hardcoded
-        I will make it more general later.
-        """
-
-        self.chunk_size = chunk_size
-        self._offset = 0
-        self._cpu_buffer = torch.empty(chunk_size, dtype=torch.float, device=torch.device("cpu:0"), pin_memory=True)
-        self._cuda_buffer = torch.empty(chunk_size,
-                                        dtype=torch.half,
-                                        device=torch.device(f"cuda:{get_current_device()}"))
-
-        self._buffered_param_list: List[ShardedParamV2] = []
-        self._numel_list = []
-
-    def copy(self, src_param: torch.nn.Parameter, target_param: ShardedParamV2):
-        assert isinstance(target_param, ShardedParamV2)
-        assert isinstance(src_param, torch.nn.Parameter)
-
-        numel = src_param.numel()
-
-        if self._offset + numel > self.chunk_size:
-            self.flush()
-
-        assert src_param.data.device.type == 'cpu'
-        self._cpu_buffer.narrow(0, self._offset, numel).copy_(src_param.data.view(-1))
-
-        self._buffered_param_list.append(target_param)
-        self._numel_list.append(numel)
-
-        self._offset += numel
-
-    def flush(self):
-        """
-        flush to cuda memory
-        """
-        self._cuda_buffer.copy_(self._cpu_buffer)
-        flush_offset = 0
-        for sparam, numel in zip(self._buffered_param_list, self._numel_list):
-            sparam.sharded_data_tensor.copy_payload(self._cpu_buffer.narrow(0, flush_offset, numel))
-            flush_offset += numel
-
-        self.reset()
-
-    def reset(self):
-        self._buffered_param_list = []
-        self._numel_list = []
-        self._offset = 0
diff --git a/colossalai/utils/memory_utils/memory_monitor.py b/colossalai/utils/memory_utils/memory_monitor.py
deleted file mode 100644
index 38f6349a3..000000000
--- a/colossalai/utils/memory_utils/memory_monitor.py
+++ /dev/null
@@ -1,67 +0,0 @@
-#!/usr/bin/env python
-# -*- encoding: utf-8 -*-
-
-import gc
-
-import psutil
-import torch
-
-from colossalai.context.parallel_mode import ParallelMode
-from colossalai.core import global_context as gpc
-from colossalai.logging import get_dist_logger
-
-
-def bytes_to_GB(val, decimal=2):
-    """A byte-to-Gigabyte converter, default using binary notation.
-
-    :param val: X bytes to convert
-    :return: X' GB
-    """
-    return round(val / (1024 * 1024 * 1024), decimal)
-
-
-def bytes_to_MB(val, decimal=2):
-    """A byte-to-Megabyte converter, default using binary notation.
-
-    :param val: X bytes to convert
-    :return: X' MB
-    """
-    return round(val / (1024 * 1024), decimal)
-
-
-def report_memory_usage(message, logger=None, report_cpu=False):
-    """Calculate and print RAM usage (in GB)
-
-    Args:
-        message (str): A prefix message to add in the log.
-        logger (:class:`colossalai.logging.DistributedLogger`): The logger used to record memory information.
-        report_cpu (bool, optional): Whether to report CPU memory.
-
-    Raises:
-        EnvironmentError: Raise error if no distributed environment has been initialized.
-    """
-    if not gpc.is_initialized(ParallelMode.GLOBAL):
-        raise EnvironmentError("No distributed environment is initialized")
-
-    gpu_allocated = bytes_to_MB(torch.cuda.memory_allocated())
-    gpu_max_allocated = bytes_to_MB(torch.cuda.max_memory_allocated())
-    gpu_cached = bytes_to_MB(torch.cuda.memory_reserved())
-    gpu_max_cached = bytes_to_MB(torch.cuda.max_memory_reserved())
-
-    full_log = f"{message}: GPU: allocated {gpu_allocated} MB, max allocated {gpu_max_allocated} MB, " \
-        + f"cached: {gpu_cached} MB, max cached: {gpu_max_cached} MB"
-
-    if report_cpu:
-        # python doesn't do real-time garbage collection so do it explicitly to get the correct RAM reports
-        gc.collect()
-        vm_stats = psutil.virtual_memory()
-        vm_used = bytes_to_MB(vm_stats.total - vm_stats.available)
-        full_log += f", CPU Virtual Memory: used = {vm_used} MB, percent = {vm_stats.percent}%"
-
-    if logger is None:
-        logger = get_dist_logger()
-    logger.info(full_log)
-
-    # get the peak memory to report correct data, so reset the counter for the next call
-    if hasattr(torch.cuda, "reset_peak_memory_stats"):    # pytorch 1.4+
-        torch.cuda.reset_peak_memory_stats()
diff --git a/colossalai/utils/memory_utils/utils.py b/colossalai/utils/memory_utils/utils.py
deleted file mode 100644
index ca0e974bc..000000000
--- a/colossalai/utils/memory_utils/utils.py
+++ /dev/null
@@ -1,82 +0,0 @@
-import torch
-from colossalai.context.parallel_mode import ParallelMode
-from colossalai.utils import get_current_device
-
-from collections import namedtuple
-import psutil
-from colossalai.core import global_context as gpc
-
-_GLOBAL_CUDA_MEM_FRACTION = 1.0
-
-
-# copy from PatrickStar
-def _get_cpu_memory_info():
-    ps_mem_info = namedtuple("ps_mem_info", ["total", "free", "cached", "buffers", "used"])
-    try:
-        # psutil reads the memory info from /proc/memory_info,
-        # which results in returning the host memory instead of
-        # that of container.
-        # Here we try to read the container memory with method in:
-        # https://stackoverflow.com/a/46213331/5163915
-        mems = {}
-        with open("/sys/fs/cgroup/memory/memory.meminfo", "rb") as f:
-            for line in f:
-                fields = line.split()
-                mems[fields[0]] = int(fields[1]) * 1024
-        total = mems[b"MemTotal:"]
-        free = mems[b"MemFree:"]
-        cached = mems[b"Cached:"]
-        buffers = mems[b"Buffers:"]
-        used = total - free - cached - buffers
-        if used < 0:
-            used = total - free
-        mem_info = ps_mem_info(total=total, free=free, cached=cached, buffers=buffers, used=used)
-    except FileNotFoundError:
-        mems = psutil.virtual_memory()
-        mem_info = ps_mem_info(
-            total=mems.total,
-            free=mems.free,
-            cached=mems.cached,
-            buffers=mems.buffers,
-            used=mems.used,
-        )
-    return mem_info
-
-
-def colo_device_memory_used(device) -> int:
-    if not isinstance(device, torch.device):
-        device = torch.device(f"cuda:{device}")
-    if device.type == 'cpu':
-        mem_info = _get_cpu_memory_info()
-        # FIXME(jiaruifang) only work for 1-CPU multi-GPU
-        # CPU memory is sharded with all processes
-        # Not support multi-GPU multi-CPU
-        # We need a local_world_size here
-        ret = mem_info.used / gpc.get_world_size(ParallelMode.DATA)
-        return ret
-    elif device.type == 'cuda':
-        ret: int = torch.cuda.memory_allocated(device)
-        # get the peak memory to report correct data, so reset the counter for the next call
-        if hasattr(torch.cuda, "reset_peak_memory_stats"):    # pytorch 1.4+
-            torch.cuda.reset_peak_memory_stats(device)
-        return ret
-
-
-def colo_set_process_memory_fraction(ratio: float) -> None:
-    """colo_set_process_memory_fraction 
-
-    set how much cuda memory used on the gpu belonging to the current process.
-
-    Args:
-        ratio (float): a ratio between 0. ~ 1.
-    """
-    global _GLOBAL_CUDA_MEM_FRACTION
-    _GLOBAL_CUDA_MEM_FRACTION = ratio
-    torch.cuda.set_per_process_memory_fraction(_GLOBAL_CUDA_MEM_FRACTION, get_current_device())
-
-
-def colo_cuda_memory_capacity() -> float:
-    """
-    Get cuda memory capacity of the current cuda.
-    """
-    return torch.cuda.get_device_properties(get_current_device()).total_memory * _GLOBAL_CUDA_MEM_FRACTION
diff --git a/colossalai/zero/shard_utils/stateful_tensor_mgr.py b/colossalai/zero/shard_utils/stateful_tensor_mgr.py
index 877c0763c..817a383d8 100644
--- a/colossalai/zero/shard_utils/stateful_tensor_mgr.py
+++ b/colossalai/zero/shard_utils/stateful_tensor_mgr.py
@@ -5,7 +5,7 @@ from colossalai.utils.cuda import get_current_device
 from colossalai.zero.sharded_param.sharded_param import ShardedParamV2
 from colossalai.zero.sharded_param.tensorful_state import StatefulTensor, TensorState
 from colossalai.zero.shard_utils.tensor_utils import colo_model_data_tensor_move_inline, colo_tensor_mem_usage
-from colossalai.utils.memory_utils.utils import colo_cuda_memory_capacity
+from colossalai.utils.memory import colo_device_memory_capacity
 from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
 from typing import Dict, List
 from colossalai.utils.memory_tracer import MemStatsCollector
@@ -64,7 +64,7 @@ class StatefulTensorMgr(object):
                     cuda_demand += colo_tensor_mem_usage(tensor.payload)[1]
             else:
                 raise RuntimeError
-        cuda_capacity = colo_cuda_memory_capacity()
+        cuda_capacity = colo_device_memory_capacity(get_current_device())
 
         if self._warmup:
             # We designate a part of CUDA memory for model data in warmup iterations.
diff --git a/colossalai/zero/shard_utils/tensor_shard_strategy.py b/colossalai/zero/shard_utils/tensor_shard_strategy.py
index 01803fed0..761143cf3 100644
--- a/colossalai/zero/shard_utils/tensor_shard_strategy.py
+++ b/colossalai/zero/shard_utils/tensor_shard_strategy.py
@@ -33,7 +33,7 @@ class TensorShardStrategy(BaseShardStrategy):
         if t.is_sharded:
             return
         if t.payload.device.type == 'cuda':
-            assert t.payload.device.index == get_current_device(), f"shard tensor on cuda device index {t.payload.device.index},"\
+            assert t.payload.device == get_current_device(), f"shard tensor on cuda device index {t.payload.device.index},"\
                 f" but current cuda device is {get_current_device()}"
         sharded_payload, _ = get_shard(t.payload, dist.get_rank(process_group), dist.get_world_size(process_group))
         t.reset_payload(sharded_payload)
diff --git a/colossalai/zero/sharded_model/sharded_model_v2.py b/colossalai/zero/sharded_model/sharded_model_v2.py
index ef2436b7f..2be5bac43 100644
--- a/colossalai/zero/sharded_model/sharded_model_v2.py
+++ b/colossalai/zero/sharded_model/sharded_model_v2.py
@@ -16,7 +16,7 @@ from colossalai.utils import get_current_device, disposable
 from colossalai.utils.memory_tracer.memstats_collector import MemStatsCollector
 from colossalai.utils.memory_tracer.model_data_memtracer import \
     GLOBAL_MODEL_DATA_TRACER
-from colossalai.utils.memory_utils.utils import colo_cuda_memory_capacity
+from colossalai.utils.memory import colo_device_memory_capacity
 from colossalai.zero.shard_utils import BaseShardStrategy
 from colossalai.zero.shard_utils.tensor_utils import colo_model_data_move_to_cpu
 from colossalai.zero.sharded_model.reduce_scatter import ReduceScatterBucketer
@@ -231,7 +231,7 @@ class ShardedModelV2(nn.Module):
             # the way to calculate margin space is based on the assumption that
             # model data is fixed in cuda during training.
             # cuda margin space can be used to store OS.
-            self._cuda_margin_space = colo_cuda_memory_capacity() - max(
+            self._cuda_margin_space = colo_device_memory_capacity(get_current_device()) - max(
                 self._memstats_collector.overall_mem_stats('cuda'))
 
     @torch.no_grad()
diff --git a/tests/test_moe/test_moe_zero_init.py b/tests/test_moe/test_moe_zero_init.py
index 309692285..4e62c77e9 100644
--- a/tests/test_moe/test_moe_zero_init.py
+++ b/tests/test_moe/test_moe_zero_init.py
@@ -41,7 +41,7 @@ def run_moe_zero_init(init_device_type, shard_strategy_class):
     logger = get_dist_logger("test_moe_zero_init")
 
     if init_device_type == 'cuda':
-        init_device = torch.device(f"cuda:{get_current_device()}")
+        init_device = get_current_device()
     elif init_device_type == 'cpu':
         init_device = torch.device("cpu")
     else:
diff --git a/tests/test_moe/test_moe_zero_optim.py b/tests/test_moe/test_moe_zero_optim.py
index 8348e093c..7956f86f4 100644
--- a/tests/test_moe/test_moe_zero_optim.py
+++ b/tests/test_moe/test_moe_zero_optim.py
@@ -62,10 +62,9 @@ def _run_test_sharded_optim_v2(cpu_offload,
     get_components_func = non_distributed_component_funcs.get_callable('no_leaf_module')
     _, train_dataloader, _, optimizer_class, criterion = get_components_func()
 
-    with ZeroInitContext(
-            target_device=torch.device('cpu') if cpu_offload else torch.device(f'cuda:{get_current_device()}'),
-            shard_strategy=shard_strategy,
-            shard_param=True):
+    with ZeroInitContext(target_device=torch.device('cpu') if cpu_offload else get_current_device(),
+                         shard_strategy=shard_strategy,
+                         shard_param=True):
         zero_model = MoeModel()
 
     zero_model = ShardedModelV2(zero_model,
diff --git a/tests/test_utils/test_bucket_tensor_copy.py b/tests/test_utils/test_bucket_tensor_copy.py
deleted file mode 100644
index f190cb522..000000000
--- a/tests/test_utils/test_bucket_tensor_copy.py
+++ /dev/null
@@ -1,39 +0,0 @@
-from colossalai.utils.memory_utils.bucket_tensor_copy import BucketizedTensorCopy
-from colossalai.zero.sharded_param import ShardedParamV2
-from colossalai.utils import free_port
-import torch
-import colossalai
-
-
-def test_bucket_copy():
-    # init dist env
-    colossalai.launch(config={}, rank=0, world_size=1, host='localhost', port=free_port(), backend='nccl')
-
-    copyer = BucketizedTensorCopy(20)
-
-    shape_list = [(2, 3), (5), (8), (12)]
-    src_param_list = []
-    tgt_param_list = []
-    for shape in shape_list:
-        # on CPU
-        src_param = torch.nn.Parameter(torch.randn(shape, dtype=torch.float, device=torch.device('cpu')))
-        # on GPU
-        tgt_param = ShardedParamV2(torch.nn.Parameter(torch.ones(shape, dtype=torch.half, device=torch.device('cuda'))))
-
-        src_param_list.append(src_param)
-        tgt_param_list.append(tgt_param)
-
-        copyer.copy(src_param, tgt_param)
-
-    copyer.flush()
-
-    for src_param, tgt_param in zip(src_param_list, tgt_param_list):
-        diff = src_param.cpu().float() - tgt_param.sharded_data_tensor.payload.cpu().float()
-        assert torch.allclose(src_param.cpu().float(),
-                              tgt_param.sharded_data_tensor.payload.cpu().float(),
-                              rtol=1e-03,
-                              atol=1e-03), f"diff {diff}"
-
-
-if __name__ == '__main__':
-    test_bucket_copy()
diff --git a/tests/test_utils/test_tensor_move.py b/tests/test_utils/test_tensor_move.py
index 500e81f1f..62874d652 100644
--- a/tests/test_utils/test_tensor_move.py
+++ b/tests/test_utils/test_tensor_move.py
@@ -2,7 +2,7 @@ import pytest
 
 from colossalai.utils.cuda import get_current_device
 from colossalai.zero.shard_utils.tensor_utils import colo_tensor_mem_usage, colo_model_data_tensor_move, colo_model_data_tensor_move_inline, colo_model_data_move_to_cpu, colo_model_tensor_clone
-from colossalai.utils.memory_utils.utils import colo_set_process_memory_fraction, colo_cuda_memory_capacity
+from colossalai.utils.memory import colo_set_process_memory_fraction, colo_device_memory_capacity
 from colossalai.utils import free_port
 from colossalai.zero.sharded_param.tensorful_state import StatefulTensor
 import colossalai
@@ -12,54 +12,63 @@ import torch
 from functools import partial
 import torch.multiprocessing as mp
 
+
 def _run_colo_tensor_mem_usage():
     for i in range(1):
         if i == 1:
-            t1 = StatefulTensor(torch.randn(2,2))
-            t2 = StatefulTensor(torch.randn(4,4))
-            c1 , g1 = colo_tensor_mem_usage(t1)
-            c2 , g2 = colo_tensor_mem_usage(t2)
-            assert c1*4 == c2
-            assert g1*4 == g2
+            t1 = StatefulTensor(torch.randn(2, 2))
+            t2 = StatefulTensor(torch.randn(4, 4))
+            c1, g1 = colo_tensor_mem_usage(t1)
+            c2, g2 = colo_tensor_mem_usage(t2)
+            assert c1 * 4 == c2
+            assert g1 * 4 == g2
         else:
-            t1 = torch.randn(2,2)
-            t2 = torch.randn(4,4)
-            c1 , g1 = colo_tensor_mem_usage(t1)
-            c2 , g2 = colo_tensor_mem_usage(t2)
-            assert c1*4 == c2
-            assert g1*4 == g2
+            t1 = torch.randn(2, 2)
+            t2 = torch.randn(4, 4)
+            c1, g1 = colo_tensor_mem_usage(t1)
+            c2, g2 = colo_tensor_mem_usage(t2)
+            assert c1 * 4 == c2
+            assert g1 * 4 == g2
 
-def _run_colo_set_process_memory_fraction_and_colo_cuda_memory_capacity():
-    frac1 = colo_cuda_memory_capacity()
+
+def _run_colo_set_process_memory_fraction_and_colo_device_memory_capacity():
+    frac1 = colo_device_memory_capacity(get_current_device())
     colo_set_process_memory_fraction(0.5)
-    frac2 = colo_cuda_memory_capacity()
-    assert frac2*2 == frac1
+    frac2 = colo_device_memory_capacity(get_current_device())
+    assert frac2 * 2 == frac1
+
 
 def _run_colo_model_data_tensor_move_inline():
-    for t in [StatefulTensor(torch.randn(2,3)), torch.randn(2,3)]:
-        colo_model_data_tensor_move_inline(t, torch.device(f"cuda:{get_current_device()}"))
-        assert t.device == torch.device(f"cuda:{get_current_device()}")
+    for t in [StatefulTensor(torch.randn(2, 3)), torch.randn(2, 3)]:
+        colo_model_data_tensor_move_inline(t, get_current_device())
+        assert t.device == get_current_device()
+
 
 def _run_colo_model_data_tensor_move():
-    for t in [(StatefulTensor(torch.ones(2, 3)), StatefulTensor(torch.zeros(2, 3).cuda(get_current_device()))),
-        (torch.ones(2, 3), torch.zeros(2, 3).cuda(get_current_device()))]:
+    for t in [(StatefulTensor(torch.ones(2, 3)), StatefulTensor(torch.zeros(2, 3).to(get_current_device()))),
+              (torch.ones(2, 3), torch.zeros(2, 3).to(get_current_device()))]:
         cpu_t, cuda_t = t
         colo_model_data_tensor_move(cpu_t, cuda_t)
-        assert cuda_t.device == torch.device(f"cuda:{get_current_device()}")
+        assert cuda_t.device == get_current_device()
+
 
 def _run_colo_model_data_move_to_cpu():
-    for t in [StatefulTensor(torch.randn(2,2)), torch.randn(4,4)]:
+    for t in [StatefulTensor(torch.randn(2, 2)), torch.randn(4, 4)]:
         colo_model_data_move_to_cpu(t)
         assert t.device == torch.device("cpu")
 
+
 def _run_colo_model_tensor_clone():
-    for t in [StatefulTensor(torch.randn(2,2).cuda(torch.cuda.current_device())), torch.randn(4,4).cuda(torch.cuda.current_device())]:
+    for t in [
+            StatefulTensor(torch.randn(2, 2).cuda(torch.cuda.current_device())),
+            torch.randn(4, 4).cuda(torch.cuda.current_device())
+    ]:
         if issubclass(type(t), StatefulTensor):
-            assert t.payload.device == torch.device(f"cuda:{get_current_device()}")
+            assert t.payload.device == get_current_device()
         else:
-            assert t.device == torch.device(f"cuda:{get_current_device()}")
-        p = colo_model_tensor_clone(t, torch.device(f"cuda:{get_current_device()}"))
-        assert p.device == torch.device(f"cuda:{get_current_device()}")
+            assert t.device == get_current_device()
+        p = colo_model_tensor_clone(t, get_current_device())
+        assert p.device == get_current_device()
         for i in range(2):
             for j in range(2):
                 if issubclass(type(t), StatefulTensor):
@@ -70,21 +79,22 @@ def _run_colo_model_tensor_clone():
                     assert t[i][j] == p[i][j]
 
 
-
 def run_dist(rank, world_size, port):
     colossalai.launch(config={}, rank=rank, world_size=world_size, host='localhost', port=port, backend='nccl')
-    _run_colo_set_process_memory_fraction_and_colo_cuda_memory_capacity()
+    _run_colo_set_process_memory_fraction_and_colo_device_memory_capacity()
     _run_colo_model_data_tensor_move_inline()
     _run_colo_model_data_tensor_move()
     _run_colo_tensor_mem_usage()
     _run_colo_model_data_move_to_cpu()
     _run_colo_model_tensor_clone()
 
+
 @pytest.mark.dist
 @pytest.mark.parametrize("world_size", [4, 5])
 def test_tensor_move(world_size):
     run_func = partial(run_dist, world_size=world_size, port=free_port())
     mp.spawn(run_func, nprocs=world_size)
 
+
 if __name__ == '__main__':
     test_tensor_move(4)
diff --git a/tests/test_zero_data_parallel/test_init_context.py b/tests/test_zero_data_parallel/test_init_context.py
index 094227b6d..34777c6b8 100644
--- a/tests/test_zero_data_parallel/test_init_context.py
+++ b/tests/test_zero_data_parallel/test_init_context.py
@@ -13,7 +13,7 @@ from colossalai.utils import free_port
 from colossalai.utils.cuda import get_current_device
 from colossalai.utils.memory_tracer.model_data_memtracer import \
     colo_model_mem_usage
-from colossalai.utils.memory_utils.utils import colo_device_memory_used
+from colossalai.utils.memory import colo_device_memory_used
 from colossalai.zero.init_ctx import ZeroInitContext
 from colossalai.zero.shard_utils import (BucketTensorShardStrategy, TensorShardStrategy)
 from tests.components_to_test.registry import non_distributed_component_funcs
@@ -29,7 +29,7 @@ def run_model_test(init_device_type, shard_strategy_class):
     for get_components_func in non_distributed_component_funcs:
         model_builder, _, _, _, _ = get_components_func()
         if init_device_type == 'cuda':
-            init_device = torch.device(f"cuda:{get_current_device()}")
+            init_device = get_current_device()
         elif init_device_type == 'cpu':
             init_device = torch.device("cpu")
         else:
diff --git a/tests/test_zero_data_parallel/test_sharded_optim_v2.py b/tests/test_zero_data_parallel/test_sharded_optim_v2.py
index 01339cc34..0c8f8ea66 100644
--- a/tests/test_zero_data_parallel/test_sharded_optim_v2.py
+++ b/tests/test_zero_data_parallel/test_sharded_optim_v2.py
@@ -57,10 +57,9 @@ def _run_test_sharded_optim_v2(cpu_offload, shard_strategy_class, use_cpuadam, g
         get_components_func = non_distributed_component_funcs.get_callable(model_name)
         model_builder, train_dataloader, _, optimizer_class, criterion = get_components_func()
 
-        with ZeroInitContext(
-                target_device=torch.device(f'cpu:0') if cpu_offload else torch.device(f'cuda:{get_current_device()}'),
-                shard_strategy=shard_strategy,
-                shard_param=True):
+        with ZeroInitContext(target_device=torch.device(f'cpu:0') if cpu_offload else get_current_device(),
+                             shard_strategy=shard_strategy,
+                             shard_param=True):
             zero_model = model_builder(checkpoint=True)
         zero_model = ShardedModelV2(
             zero_model,
diff --git a/tests/test_zero_data_parallel/test_stateful_tensor_mgr.py b/tests/test_zero_data_parallel/test_stateful_tensor_mgr.py
index 857dad5ea..af8165de2 100644
--- a/tests/test_zero_data_parallel/test_stateful_tensor_mgr.py
+++ b/tests/test_zero_data_parallel/test_stateful_tensor_mgr.py
@@ -2,9 +2,10 @@ import torch
 import colossalai
 import pytest
 import torch.multiprocessing as mp
+from colossalai.utils.cuda import get_current_device
 from colossalai.utils.memory_tracer import MemStatsCollector
 from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
-from colossalai.utils.memory_utils.utils import colo_cuda_memory_capacity, colo_set_process_memory_fraction
+from colossalai.utils.memory import colo_device_memory_capacity, colo_set_process_memory_fraction
 from colossalai.zero.shard_utils import StatefulTensorMgr
 from colossalai.zero.sharded_param.sharded_param import ShardedParamV2
 from colossalai.zero.sharded_param.tensorful_state import TensorState
@@ -26,7 +27,7 @@ class Net(torch.nn.Module):
 
 
 def run_stm():
-    cuda_capacity = colo_cuda_memory_capacity()
+    cuda_capacity = colo_device_memory_capacity(get_current_device())
     fraction = (1.4 * 1024**3) / cuda_capacity
     # limit max memory to 1.4GB
     # which means only 2 parameters can be on CUDA