# After I updated Anaconda, sampling with Pymc3 became very slow

**URL:** <https://discourse.pymc.io/t/after-i-updated-anaconda-sampling-with-pymc3-became-very-slow/7865>\
**Category:** Questions\
**Created:** [August 9, 2021, 11:10pm UTC](https://discourse.pymc.io/t/after-i-updated-anaconda-sampling-with-pymc3-became-very-slow/7865 "2021-08-09T23:10:52Z")\
**Posts on this page:** 1\
**Showing post:** 8

<div class="post-metadata">

**Author:** ![Jym0502](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/jym0502/32/3066_2.png) [@Jym0502](https://discourse.pymc.io/u/Jym0502)\
**Post date:** [August 23, 2021, 7:26am UTC](https://discourse.pymc.io/t/after-i-updated-anaconda-sampling-with-pymc3-became-very-slow/7865/8 "2021-08-23T07:26:25Z")

</div>

I reinstalled my pymc3 by anaconda, but the sampling speed is quite slow, almost 10 times slower than before I updated my anaconda.

So I tried to find the reason from warning:

- Firstly,

```auto
WARNING (theano.configdefaults): g++ not available, if using conda: `conda install m2w64-toolchain`
C:\Users\admin\anaconda3\lib\site-packages\theano\configdefaults.py:560: UserWarning: DeprecationWarning: there is no c++ compiler.This is deprecated and with Theano 0.11 a c++ compiler will be mandatory
  warnings.warn("DeprecationWarning: there is no c++ compiler."
WARNING (theano.configdefaults): g++ not detected ! Theano will be unable to execute optimized C-implementations (for both CPU and GPU) and will default to Python implementations. Performance will be severely degraded. To remove this warning, set Theano flags cxx to an empty string.

```

Although I try to install m2w64-toolchain, I cannot slove this warning.  
I found how to install g++ but failed.

Here is my version of m2w64:

m2w64-binutils 2.25.1 5 conda-forge  
m2w64-bzip2 1.0.6 6 conda-forge  
m2w64-crt-git 5.0.0.4636.2595836 2 conda-forge  
m2w64-gcc 5.3.0 6 conda-forge  
m2w64-gcc-ada 5.3.0 6 conda-forge  
m2w64-gcc-fortran 5.3.0 6 conda-forge  
m2w64-gcc-libgfortran 5.3.0 6 conda-forge  
m2w64-gcc-libs 5.3.0 7 conda-forge  
m2w64-gcc-libs-core 5.3.0 7 conda-forge  
m2w64-gcc-objc 5.3.0 6 conda-forge  
m2w64-gmp 6.1.0 2 conda-forge  
m2w64-headers-git 5.0.0.4636.c0ad18a 2 conda-forge  
m2w64-isl 0.16.1 2 conda-forge  
m2w64-libiconv 1.14 6 conda-forge  
m2w64-libmangle-git 5.0.0.4509.2e5a9a2 2 conda-forge  
m2w64-libwinpthread-git 5.0.0.4634.697f757 2 conda-forge  
m2w64-make 4.1.2351.a80a8b8 2 conda-forge  
m2w64-mpc 1.0.3 3 conda-forge  
m2w64-mpfr 3.1.4 4 conda-forge  
m2w64-pkg-config 0.29.1 2 conda-forge  
m2w64-toolchain 5.3.0 7 conda-forge  
m2w64-toolchain\_win-64 2.4.0 0 conda-forge  
m2w64-tools-git 5.0.0.4592.90b8472 2 conda-forge  
m2w64-windows-default-manifest 6.4 3 conda-forge  
m2w64-winpthreads-git 5.0.0.4634.697f757 2 conda-forge  
m2w64-zlib 1.2.8 10 conda-forge

- Secondly,

```auto
WARNING (theano.tensor.blas): Using NumPy C-API based implementation for BLAS functions.

```

From [here](https://discourse.pymc.io/t/warning-theano-tensor-blas-using-numpy-c-api-based-implementation-for-blas-functions-help/3228/4), I knew that it seems to be the reason for the slow sampling, but I tried the code as followed,

```auto
conda install numpy scipy mkl
conda install theano pygpu
conda install pymc3

```

but nothing changed. The warning stills occurred.

---

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