# Cmake problem: "The CUDA compiler identification is unknown"
**URL:** https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307
**Category:** User discussions
**Created:** [June 5, 2024, 9:32am UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307 "2024-06-05T09:32:57Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@eisoab](https://gromacs.bioexcel.eu/u/eisoab)
#### Post date: [June 5, 2024, 9:32am UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/1 "2024-06-05T09:32:57Z")
GROMACS version: gromacs-2024.2
I’m trying to compile gromacs on a Xeon E-2174G with a nvidia Quadro P2000 an fresh almalinux9.4 installation, but I’m getting stuck on a cuda issue after running cmake like this:
```auto
cmake .. -DGMX_BUILD_OWN_FFTW=ON -DREGRESScmake .. -DGMX_BUILD_OWN_FFTW=ON -DREGRESSIONTEST_DOWNLOAD=ON -DGMX_GPU=CUDA
IONTEST_DOWNLOAD=ON -DGMX_GPU=CUDA
[...]
-- The CUDA compiler identification is unknown
CMake Error at /usr/share/cmake/Modules/CMakeDetermineCUDACompiler.cmake:603 (message):
Failed to detect a default CUDA architecture.
Compiler output:
Call Stack (most recent call first):
cmake/gmxManageCuda.cmake:116 (enable_language)
CMakeLists.txt:697 (include)
```
some output that may be relevant
```auto
[...]
-- Found CUDA: /usr/local/cuda (found suitable version "12.5", minimum required is "11.0")
-- Adding work-around for issue compiling CUDA code with glibc 2.23 string.h
-- Check for working NVCC/C++ compiler combination with nvcc '/usr/local/cuda/bin/nvcc'
-- Check for working NVCC/C++ compiler combination - works
[...[
```
using cuda-11.8 doesn’t seem to make a difference.
Any idea how to fix this?
Thanks, Eiso
---
### Author:  [@EishaKhilji](https://gromacs.bioexcel.eu/u/EishaKhilji)
#### Post date: [June 8, 2024, 6:50pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/2 "2024-06-08T18:50:23Z")
Hello, I am facing the same issue, did you get any solution?
I have tried multiple solutions available on user forums but all in vain.
make version: 3.29.3 CUDA toolkit: 12.5 gcc version:9.4.0
---
### Author:  [@eisoab](https://gromacs.bioexcel.eu/u/eisoab)
#### Post date: [June 12, 2024, 11:39pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/3 "2024-06-12T23:39:58Z")
Hi,
In the end it worked, but not sure what did the trick …
either adding `-D CMAKE_CUDA_ARCHITECTURES=native`
cmake … -DGMX\_BUILD\_OWN\_FFTW=ON -DREGRESSIONTEST\_DOWNLOAD=ON -DGMX\_GPU=CUDA **-D CMAKE\_CUDA\_ARCHITECTURES=native**
or this:
`dnf install libcudnn8-devel libcudnn8 cudnn`
or both.
Eiso
---
### Author:  [@EishaKhilji](https://gromacs.bioexcel.eu/u/EishaKhilji)
#### Post date: [June 14, 2024, 11:38am UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/4 "2024-06-14T11:38:05Z")
By this command :
sudo cmake … -DGMX\_BUILD\_OWN\_FFTW=ON -DREGRESSIONTEST\_DOWNLOAD=ON -DGMX\_GPU=CUDA -D CMAKE\_CUDA\_ARCHITECTURES=native
I got the following error:
– The CUDA compiler identification is unknown
CMake Error at cmake/gmxManageCuda.cmake:116 (enable\_language):
No CMAKE\_CUDA\_COMPILER could be found.
Tell CMake where to find the compiler by setting either the environment
variable “CUDACXX” or the CMake cache entry CMAKE\_CUDA\_COMPILER to the full
path to the compiler, or to the compiler name if it is in the PATH.
Call Stack (most recent call first):
CMakeLists.txt:697 (include)
---
### Author:  [@EishaKhilji](https://gromacs.bioexcel.eu/u/EishaKhilji)
#### Post date: [June 15, 2024, 7:35pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/5 "2024-06-15T19:35:13Z")
Thanks,
This command worked for me after upgrading gcc version from 9 to 13:
sudo cmake … -DGMX\_BUILD\_OWN\_FFTW=ON -DREGRESSIONTEST\_DOWNLOAD=ON -DGMX\_GPU=CUDA -DCMAKE\_PREFIX\_PATH=/usr/local/cuda-12.5
---
### Author:  [@MFaizal](https://gromacs.bioexcel.eu/u/MFaizal)
#### Post date: [December 21, 2024, 5:40am UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/6 "2024-12-21T05:40:51Z")
Thank you guys for the suggestions.
This command worked for me:
cmake … -DGMX\_BUILD\_OWN\_FFTW=ON -DREGRESSIONTEST\_DOWNLOAD=ON -DGMX\_GPU=CUDA -DCMAKE\_PREFIX\_PATH=/usr/local/cuda-12.6 -DCMAKE\_CUDA\_ARCHITECTURES=native
OS: Ubuntu 24.04 LTS
GROMACS version: gromacs-2024.4
Processor: Intel Xeon X5660
GPU: Nvidia RTX3080
NVIDIA-SMI: 560.35.05
CUDA version: 12.6
cmake version: 3.28.3
gcc version: 13.3.0
---
### Author:  [@asim.rs](https://gromacs.bioexcel.eu/u/asim.rs)
#### Post date: [January 10, 2025, 1:44pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/7 "2025-01-10T13:44:37Z")
I have tried to enable gpu by the use of `-D CMAKE_CUDA_ARCHITECTURES=native` but in reply " cmake … -DGMX\_BUILD\_OWN\_FFTW=ON -DREGRESSIONTEST\_DOWNLOAD=ON -DGMX\_GPU=CUDA -D CMAKE\_CUDA\_ARCHITECTURES=native
CMake Error: The source directory “/home/sanghamitra-dey/Downloads/gromacs-2024.4/build/…” does not exist.
Specify --help for usage, or press the help button on the CMake GUI." I got this. So can you please help me out? Please.
---
### Author:  [@al42and](https://gromacs.bioexcel.eu/u/al42and)
#### Post date: [January 10, 2025, 6:45pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/8 "2025-01-10T18:45:12Z")
> [@asim.rs](#):
>
> `cmake ...`
Should be `cmake ..`. Some people set up `...` to alias `../..` or `..` for convenience.
---
### Author:  [@edivaldosrodrigues](https://gromacs.bioexcel.eu/u/edivaldosrodrigues)
#### Post date: [March 18, 2025, 9:34pm UTC](https://gromacs.bioexcel.eu/t/cmake-problem-the-cuda-compiler-identification-is-unknown/9307/9 "2025-03-18T21:34:50Z")
> [@EishaKhilji](#):
>
> -DCMAKE\_PREFIX\_PATH=/usr/local/cuda-12.5
this also worked for me