# CUDA does not successfully initialise

**URL:** <https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661>\
**Category:** GPU\
**Tags:** cuda\
**Created:** [December 31, 2020, 3:39pm UTC](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661 "2020-12-31T15:39:06Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![iHany](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ihany/32/18151_2.png) [@iHany](https://discourse.julialang.org/u/iHany)\
**Post date:** [December 31, 2020, 3:39pm UTC](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661/1 "2020-12-31T15:39:06Z")

</div>

I installed `CUDA` by `]add CUDA` and tried to test it by `test CUDA`.  
However, I encountered the below error message.

## CUDA initialisation error

```juliaREPL
ERROR: LoadError: CUDA.jl did not successfully initialize, and is not usable.
If you did not see any other error message, try again in a new session
with the JULIA_DEBUG environment variable set to 'CUDA'.

```

And this message is popped up every time I try to use any functionality of `CUDA`, for example,

## cu error

```juliaREPL
julia> using CUDA

julia> cu(rand(5))
ERROR: CUDA.jl did not successfully initialize, and is not usable.
If you did not see any other error message, try again in a new session
with the JULIA_DEBUG environment variable set to 'CUDA'.
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] libcuda() at /home/jinrae/.julia/packages/CUDA/YeS8q/src/initialization.jl:51
 [3] (::CUDA.var"#690#cache_fptr!#9")() at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/utils/call.jl:31
 [4] macro expansion at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/utils/call.jl:39 [inlined]
 [5] macro expansion at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/cudadrv/libcuda.jl:29 [inlined]
 [6] macro expansion at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/cudadrv/error.jl:102 [inlined]
 [7] cuDeviceGet(::Base.RefValue{Int32}, ::Int64) at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/utils/call.jl:93
 [8] CuDevice(::Int64) at /home/jinrae/.julia/packages/CUDA/YeS8q/lib/cudadrv/devices.jl:25
 [9] initialize_thread(::Int64) at /home/jinrae/.julia/packages/CUDA/YeS8q/src/state.jl:121
 [10] prepare_cuda_call() at /home/jinrae/.julia/packages/CUDA/YeS8q/src/state.jl:80
 [11] device at /home/jinrae/.julia/packages/CUDA/YeS8q/src/state.jl:227 [inlined]
 [12] alloc at /home/jinrae/.julia/packages/CUDA/YeS8q/src/pool.jl:293 [inlined]
 [13] CuArray{Float32,1}(::UndefInitializer, ::Tuple{Int64}) at /home/jinrae/.julia/packages/CUDA/YeS8q/src/array.jl:20
 [14] CuArray at /home/jinrae/.julia/packages/CUDA/YeS8q/src/array.jl:76 [inlined]
 [15] similar at ./abstractarray.jl:675 [inlined]
 [16] convert(::Type{CuArray{Float32,N} where N}, ::Array{Float64,1}) at /home/jinrae/.julia/packages/GPUArrays/jhRU7/src/host/construction.jl:82
 [17] adapt_storage at /home/jinrae/.julia/packages/CUDA/YeS8q/src/array.jl:330 [inlined]
 [18] adapt_structure at /home/jinrae/.julia/packages/Adapt/8kQMV/src/Adapt.jl:42 [inlined]
 [19] adapt at /home/jinrae/.julia/packages/Adapt/8kQMV/src/Adapt.jl:40 [inlined]
 [20] cu(::Array{Float64,1}) at /home/jinrae/.julia/packages/CUDA/YeS8q/src/array.jl:342
 [21] top-level scope at REPL[7]:1

```

Note: this is the result of `nvidia-smi`. It seems not use GPU at all when I tried to train a neural network by `Flux`.

What should I do?

## nvidia-smi

```bash
➜ GliderPathPlanning git:(using-gpu) ✗ nvidia-smi
Fri Jan 1 00:28:32 2021
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 455.45.01 Driver Version: 455.45.01 CUDA Version: 11.1 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 GeForce RTX 207... Off | 00000000:01:00.0 Off | N/A |
| N/A 54C P8 10W / N/A | 1500MiB / 7982MiB | 34% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| 0 N/A N/A 1092 G /usr/lib/xorg/Xorg 134MiB |
| 0 N/A N/A 1852 G /usr/lib/xorg/Xorg 840MiB |
| 0 N/A N/A 2040 G /usr/bin/gnome-shell 230MiB |
| 0 N/A N/A 2306 G ...mviewer/tv_bin/TeamViewer 2MiB |
| 0 N/A N/A 673753 G ...AAAAAAAA== --shared-files 100MiB |
| 0 N/A N/A 673779 G ...AAAAAAAA== --shared-files 176MiB |
+-----------------------------------------------------------------------------+

```

## CUDA.has\_cuda()

```juliaREPL
julia> CUDA.has_cuda()
false

```

---

<div class="post-metadata">

**Author:** ![iHany](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ihany/32/18151_2.png) [@iHany](https://discourse.julialang.org/u/iHany)\
**Post date:** [December 31, 2020, 3:48pm UTC](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661/2 "2020-12-31T15:48:07Z")

</div>

I don’t know why but after turned off my laptop the error disappeared.  
I have no idea why it works ☹

---

<div class="post-metadata">

**Author:** ![maleadt](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/maleadt/32/10097_2.png) [@maleadt](https://discourse.julialang.org/u/maleadt)\
**Post date:** [January 4, 2021, 7:20am UTC](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661/3 "2021-01-04T07:20:24Z")

</div>

> [@iHany](#):
>
> ```julia
> try again in a new session
> with the JULIA_DEBUG environment variable set to 'CUDA'.
> 
> ```

Did you try that suggestion?