PyTorch is not compiled with NCCL support

username: tianle-BigRice
cooked: <p>when i used dataparell ,i meet :\anaconda3\lib\site-packages\torch\cuda\nccl.py:16: UserWarning: PyTorch is not compiled with NCCL support warnings.warn(‘PyTorch is not compiled with NCCL support’)<br>
But I used to use it normally ,when i update torch1.5-torch1.7,the question is coming. why?<br>
my code is</p>
<pre><code class="lang-auto">    if t.cuda.device_count() &gt; 1:
        model = nn.DataParallel(model)
    if opt.use_gpu: model.cuda()
</code></pre>
<p>i meet the answer :<a href="https://discuss.pytorch.org/t/win10-pytorch-dataparallel-got-warning-pytorch-is-not-compiled-with-nccl-support/15393" class="inline-onebox">Win10+PyTorch+DataParallel got warning:"PyTorch is not compiled with NCCL support"</a><br>
i want to konw why torch 1.5.1 can be used dataparallel ,but 1.7.0 doesnt.<br>
could someone answer this question for me?<br>
I went back to 1.5.1 and couldn’t use it either</p>
<pre><code class="lang-auto">:\anaconda3\lib\site-packages\torch\cuda\nccl.py:24: UserWarning: PyTorch is not compiled with NCCL support
  warnings.warn('PyTorch is not compiled with NCCL support')
  0%|                                                                                        | 0/12097 [00:06&lt;?, ?it/s]
Traceback (most recent call last):
  File "main.py", line 188, in &lt;module&gt;
    fire.Fire()
  File "d:\anaconda3\lib\site-packages\fire\core.py", line 138, in Fire
    component_trace = _Fire(component, args, parsed_flag_args, context, name)
  File "d:\anaconda3\lib\site-packages\fire\core.py", line 468, in _Fire
    target=component.__name__)
  File "d:\anaconda3\lib\site-packages\fire\core.py", line 672, in _CallAndUpdateTrace
    component = fn(*varargs, **kwargs)
  File "main.py", line 103, in train
    optimizer.step()
  File "d:\anaconda3\lib\site-packages\torch\autograd\grad_mode.py", line 15, in decorate_context
    return func(*args, **kwargs)
  File "d:\anaconda3\lib\site-packages\torch\optim\adam.py", line 107, in step
    denom = (exp_avg_sq.sqrt() / math.sqrt(bias_correction2)).add_(group['eps'])
RuntimeError: CUDA out of memory. Tried to allocate 2.18 GiB (GPU 0; 15.92 GiB total capacity; 13.74 GiB already allocated; 666.81 MiB free; 14.59 GiB reserved in total by PyTorch)
</code></pre>
<p>I would be very grateful<br>
thank you</p>
<p>is anybody there ， i need help。 <img src="https://discuss.pytorch.org/images/emoji/apple/joy.png?v=9" title=":joy:" class="emoji" alt=":joy:"></p>

username: tianle-BigRice
cooked: <p>the nvidia-smi is<br>
<img src="https://discuss.pytorch.org/uploads/default/original/3X/b/5/b5a8f44c968468b5d93fb71a27540fa05f1eab39.jpeg" alt="{1E273534-151D-44ED-848E-AB67935EC396}.png" data-base62-sha1="pV2p72aScIYdUpO5miybENqNguZ" width="631" height="322"></p>

username: tianle-BigRice
cooked: <p>the question be solved ,when i remove all pkgs.and then reinstall pkgs.the question be solved.</p>

username: MaxP
cooked: <p>Hey could you maybe elaborate on how you fixed it? I´m running into the same issue and am a total noob.</p>

username: tianle-BigRice
cooked: <p>windows is not supported nccl. <img src="https://discuss.pytorch.org/images/emoji/apple/joy.png?v=9" title=":joy:" class="emoji" alt=":joy:"> <img src="https://discuss.pytorch.org/images/emoji/apple/joy.png?v=9" title=":joy:" class="emoji" alt=":joy:"></p>