# \#cudajl

**URL:** https://discourse.julialang.org/tag/cudajl/1086.md

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

---

## [Seismic imaging with Julia and CUDA.jl](https://discourse.julialang.org/t/seismic-imaging-with-julia-and-cuda-jl/139609)

<div class="topic-metadata">

**Author:** [@aalquwayfili](https://discourse.julialang.org/u/aalquwayfili)\
**Replies:** 0\
**Last updated:** [September 22, 2026, 4:05pm UTC](https://discourse.julialang.org/t/seismic-imaging-with-julia-and-cuda-jl/139609 "2026-09-22T16:05:45Z")

</div>

Hey everyone, I’ve been experimenting with seismic imaging in Julia and CUDA.jl. I built a 2D model that sends waves through rock layers, records the echoes, and reconstructs the layer boundary using reverse-time migrati…

---

## [CUDA.jl with @threads causing memory leak?](https://discourse.julialang.org/t/cuda-jl-with-threads-causing-memory-leak/136853)

<div class="topic-metadata">

**Author:** [@noetheriankoala](https://discourse.julialang.org/u/noetheriankoala)\
**Replies:** 3\
**Last updated:** [April 27, 2026, 10:23pm UTC](https://discourse.julialang.org/t/cuda-jl-with-threads-causing-memory-leak/136853 "2026-04-27T22:23:37Z")

</div>

Hello. First of all, I am using Julia v1.12.6, CUDA v5.11.2, and FLoops v0.2.2. Consider the following code and comments. using CUDA using Base.Threads function func1() A = CuArray{Float64}(undef, 1500, 1500, 1000)…

---

## [Migrating CUDA.jl atomic operations to ParallelStencil.jl using Atomix.jl?](https://discourse.julialang.org/t/migrating-cuda-jl-atomic-operations-to-parallelstencil-jl-using-atomix-jl/136710)

<div class="topic-metadata">

**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 2\
**Last updated:** [April 14, 2026, 1:57pm UTC](https://discourse.julialang.org/t/migrating-cuda-jl-atomic-operations-to-parallelstencil-jl-using-atomix-jl/136710 "2026-04-14T13:57:33Z")

</div>

Hello, I am currently porting my code from CUDA.jl to ParallelStencil.jl. While I have successfully managed the transition for mixed Float64 and ComplexF64 types, I have run into a challenge replacing CUDA-specific atom…

---

## [CUDA package having issues due to different versions of CUDA toolkit and NVIDIA driver CUDA version](https://discourse.julialang.org/t/cuda-package-having-issues-due-to-different-versions-of-cuda-toolkit-and-nvidia-driver-cuda-version/134755)

<div class="topic-metadata">

**Author:** [@Aditya747S](https://discourse.julialang.org/u/Aditya747S)\
**Replies:** 11\
**Last updated:** [January 24, 2026, 10:20pm UTC](https://discourse.julialang.org/t/cuda-package-having-issues-due-to-different-versions-of-cuda-toolkit-and-nvidia-driver-cuda-version/134755 "2026-01-24T22:20:48Z")

</div>

I have CUDA toolkit for CUDA 13.0 and my drivers have CUDA 13.1 which is why I am getting this error in julia Error: You are using CUDA 13.1.0, but CUDA.jl was precompiled for CUDA 13.0.0. │ │ This is unexpected; pleas…

---

## [Issues with Julia 1.12.2 Docker with GAP.jl](https://discourse.julialang.org/t/issues-with-julia-1-12-2-docker-with-gap-jl/134558)

<div class="topic-metadata">

**Author:** [@RYB](https://discourse.julialang.org/u/RYB)\
**Replies:** 3\
**Last updated:** [December 16, 2025, 12:27am UTC](https://discourse.julialang.org/t/issues-with-julia-1-12-2-docker-with-gap-jl/134558 "2025-12-16T00:27:18Z")

</div>

Hello, I’m relatively new to Docker and Julia so I would appreciate any advice. I am trying to create a Docker container for Julia 1.12.2 with CUDA.jl, Oscar.jl (and hence GAP.jl), and some other libraries. Namely, I wa…

---

## [Understanding random numbers in a GPU kernel](https://discourse.julialang.org/t/understanding-random-numbers-in-a-gpu-kernel/131771)

<div class="topic-metadata">

**Author:** [@jwtkeeble](https://discourse.julialang.org/u/jwtkeeble)\
**Replies:** 4\
**Last updated:** [September 1, 2025, 11:15am UTC](https://discourse.julialang.org/t/understanding-random-numbers-in-a-gpu-kernel/131771 "2025-09-01T11:15:41Z")

</div>

Hi All, I’m trying to understand the use of random numbers inside CUDA kerrnels in Julia. Below I have a simple script to estimate pi, but I have a few questions regarding its implementation. Is my implementation of r…

---

## [Trying to parallelize using CUSOLVERRF.jl with @threads](https://discourse.julialang.org/t/trying-to-parallelize-using-cusolverrf-jl-with-threads/131457)

<div class="topic-metadata">

**Author:** [@mhunke](https://discourse.julialang.org/u/mhunke)\
**Replies:** 7\
**Last updated:** [August 19, 2025, 9:09am UTC](https://discourse.julialang.org/t/trying-to-parallelize-using-cusolverrf-jl-with-threads/131457 "2025-08-19T09:09:29Z")

</div>

Hi everyone, I’m working with CUSOLVERRF.jl to solve multiple sparse linear systems on the GPU, using the high-level RFLU API: GitHub - exanauts/CUSOLVERRF.jl: A Julia wrapper for cusolverRF All systems share the same …

---

## [How to avoid memory allocation while doing sum on a GPU?](https://discourse.julialang.org/t/how-to-avoid-memory-allocation-while-doing-sum-on-a-gpu/128225)

<div class="topic-metadata">

**Author:** [@Shashank](https://discourse.julialang.org/u/Shashank)\
**Replies:** 7\
**Last updated:** [April 20, 2025, 7:00am UTC](https://discourse.julialang.org/t/how-to-avoid-memory-allocation-while-doing-sum-on-a-gpu/128225 "2025-04-20T07:00:48Z")

</div>

I have been having a problem with memory allocation when using sum on a CUDA array. Is there a way to avoid it? I have pasted the relevant parts of the code below: println("3:", CUDA.memory\_status()) Cgain1\_reshaped\_for…

---

## [Multiple Loops in Julia](https://discourse.julialang.org/t/multiple-loops-in-julia/127814)

<div class="topic-metadata">

**Author:** [@MarcoBPCode](https://discourse.julialang.org/u/MarcoBPCode)\
**Replies:** 7\
**Last updated:** [April 8, 2025, 7:47am UTC](https://discourse.julialang.org/t/multiple-loops-in-julia/127814 "2025-04-08T07:47:31Z")

</div>

HI, I’m writing a code that need multiples loops inside each other and i want to make parallelization it. Loop1{ Loop2{ Loop3{ Loop4{ … } } } } Can recommended some techique ? o maybe something to read o impl…

---

## [CUDA.jl write to global memory in PTX](https://discourse.julialang.org/t/cuda-jl-write-to-global-memory-in-ptx/127426)

<div class="topic-metadata">

**Author:** [@daniwipes](https://discourse.julialang.org/u/daniwipes)\
**Replies:** 4\
**Last updated:** [March 27, 2025, 9:31pm UTC](https://discourse.julialang.org/t/cuda-jl-write-to-global-memory-in-ptx/127426 "2025-03-27T21:31:18Z")

</div>

I am developing a transpiler for a uni project, that takes an Expr and converts that into PTX code which can then be called to evaluate that expression (in the context of symbolic regression, meaning a lot different valu…

---

## [I don't understand why it is slower with CuStaticSharedArray](https://discourse.julialang.org/t/i-dont-understand-why-it-is-slower-with-custaticsharedarray/126763)

<div class="topic-metadata">

**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 9\
**Last updated:** [March 17, 2025, 4:35pm UTC](https://discourse.julialang.org/t/i-dont-understand-why-it-is-slower-with-custaticsharedarray/126763 "2025-03-17T16:35:32Z")

</div>

Hello, I am new to Julia and I am trying to use an iterative scheme to solve a force balance equation, concretely the kernel without shared memory is quite simple: function kernel\_comp\_v\_noshmem!(vn, v, F) # Indexi…

---

## [Why is my kernel as slow in FP32 as in FP64 on A2000 Ada-based GPU?](https://discourse.julialang.org/t/why-is-my-kernel-as-slow-in-fp32-as-in-fp64-on-a2000-ada-based-gpu/126809)

<div class="topic-metadata">

**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 10\
**Last updated:** [March 11, 2025, 2:39pm UTC](https://discourse.julialang.org/t/why-is-my-kernel-as-slow-in-fp32-as-in-fp64-on-a2000-ada-based-gpu/126809 "2025-03-11T14:39:58Z")

</div>

Hello, I am new to Julia and I wanted to use Float32 to debug my code expecting it be faster as my gpu provide only 1/64 of its performance in Float64. I was surprised to see that using Float32 was almost as slow as Fl…

---

## [Symmetric view of sparse matrix CUDA.jl](https://discourse.julialang.org/t/symmetric-view-of-sparse-matrix-cuda-jl/123811)

<div class="topic-metadata">

**Author:** [@victor\_vhrn](https://discourse.julialang.org/u/victor_vhrn)\
**Replies:** 0\
**Last updated:** [December 13, 2024, 1:32pm UTC](https://discourse.julialang.org/t/symmetric-view-of-sparse-matrix-cuda-jl/123811 "2024-12-13T13:32:46Z")

</div>

What is the best way of adapting Symmetric to the GPU? Can it be done? Should it be done? I currently have the following function Aadj which I would like to create a GPU version of: using CUDA using CUDA.CUSPARSE using…

---

## [Delays shown in Nsight Systems between HtoD memcopy and kernel launch when using CUDA.jl](https://discourse.julialang.org/t/delays-shown-in-nsight-systems-between-htod-memcopy-and-kernel-launch-when-using-cuda-jl/117446)

<div class="topic-metadata">

**Author:** [@Cibin\_Joseph](https://discourse.julialang.org/u/Cibin_Joseph)\
**Replies:** 9\
**Last updated:** [July 31, 2024, 11:22pm UTC](https://discourse.julialang.org/t/delays-shown-in-nsight-systems-between-htod-memcopy-and-kernel-launch-when-using-cuda-jl/117446 "2024-07-31T23:22:04Z")

</div>

For the CUDA.jl minimal example shown below, I see a considerably large delay between the HtoD memcopy and the kernel launch. I’m not able to figure out what causes it. For a larger array, sometimes this delay is much le…

---

## [Julia with CuArray issue](https://discourse.julialang.org/t/julia-with-cuarray-issue/116485)

<div class="topic-metadata">

**Author:** [@miniskar](https://discourse.julialang.org/u/miniskar)\
**Replies:** 2\
**Last updated:** [July 1, 2024, 8:04pm UTC](https://discourse.julialang.org/t/julia-with-cuarray-issue/116485 "2024-07-01T20:04:43Z")

</div>

I am getting an issue with CuArray and tried to explain it with simple example. I have created a device pointer through cudaMalloc in C function “get\_device\_address()”. The “get\_device\_address()” is called in Julia and …

---

## [Using CUDA hangs with P100 GPU](https://discourse.julialang.org/t/using-cuda-hangs-with-p100-gpu/113337)

<div class="topic-metadata">

**Author:** [@Donald](https://discourse.julialang.org/u/Donald)\
**Replies:** 2\
**Last updated:** [April 23, 2024, 9:53am UTC](https://discourse.julialang.org/t/using-cuda-hangs-with-p100-gpu/113337 "2024-04-23T09:53:01Z")

</div>

Hello. I’m trying to install CUDA.jl inside an interactive session on a cluster node with an NVIDIA Tesla P100 GPU. The output of nvidia-smi is +--------------------------------------------------------------------------…

---

## [Cuda (Julia vs C++)](https://discourse.julialang.org/t/cuda-julia-vs-c/109865)

<div class="topic-metadata">

**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 4\
**Last updated:** [February 12, 2024, 12:03pm UTC](https://discourse.julialang.org/t/cuda-julia-vs-c/109865 "2024-02-12T12:03:44Z")

</div>

Are there any benchmarks between C++ cuda and Cuda.jl?

---

## [CUDA.jl - MethodError: no method matching CUDA.CuArray](https://discourse.julialang.org/t/cuda-jl-methoderror-no-method-matching-cuda-cuarray/107717)

<div class="topic-metadata">

**Author:** [@maria96](https://discourse.julialang.org/u/maria96)\
**Replies:** 0\
**Last updated:** [December 16, 2023, 9:03pm UTC](https://discourse.julialang.org/t/cuda-jl-methoderror-no-method-matching-cuda-cuarray/107717 "2023-12-16T21:03:36Z")

</div>

I’m training a Neural Network using NeuralEstimators.jl in julia, and I’m submitting my code in my slurm high performance computer. For some reason, it is not working now using GPUs (it was working before) but it is work…

---

## [Batched CUDA FFT Plans](https://discourse.julialang.org/t/batched-cuda-fft-plans/105187)

<div class="topic-metadata">

**Author:** [@MaximilianGelbrecht](https://discourse.julialang.org/u/MaximilianGelbrecht)\
**Replies:** 2\
**Last updated:** [October 20, 2023, 6:50am UTC](https://discourse.julialang.org/t/batched-cuda-fft-plans/105187 "2023-10-20T06:50:21Z")

</div>

CUDA.jl PR1903 added support for FFTs along more directions with CUDA.jl v5. I am a bit confused how this works in practice, as I can’t find it documented. The PR states This is achieved by allowing fft-plans to have f…

---

## [Is there any good way to call functions from a set of functions in a CUDA kernel](https://discourse.julialang.org/t/is-there-any-good-way-to-call-functions-from-a-set-of-functions-in-a-cuda-kernel/102051)

<div class="topic-metadata">

**Author:** [@huiyuxie](https://discourse.julialang.org/u/huiyuxie)\
**Replies:** 3\
**Last updated:** [July 25, 2023, 7:49pm UTC](https://discourse.julialang.org/t/is-there-any-good-way-to-call-functions-from-a-set-of-functions-in-a-cuda-kernel/102051 "2023-07-25T19:49:55Z")

</div>

Hi! I had some problem with calling functions from a function set in CUDA kernels. For example, if I define a function set like below and then call the kernel # Define function f1, f2, f3, f4, f5 ... # Create a NamedTu…

---

## [CUDAKernels not defined error in KernelAbstractions example](https://discourse.julialang.org/t/cudakernels-not-defined-error-in-kernelabstractions-example/96003)

<div class="topic-metadata">

**Author:** [@prikmm](https://discourse.julialang.org/u/prikmm)\
**Replies:** 6\
**Last updated:** [March 21, 2023, 7:21pm UTC](https://discourse.julialang.org/t/cudakernels-not-defined-error-in-kernelabstractions-example/96003 "2023-03-21T19:21:37Z")

</div>

Hi all, I am new to Julia and am currently trying to run performant\_matmul.jl example present in KernelsAbstractions.jl. I have added CUDA.jl to my environment which I created using activate & instantiate using the Proj…

---

## [CUDA.jl kernel is half as fast as c++ Kernel](https://discourse.julialang.org/t/cuda-jl-kernel-is-half-as-fast-as-c-kernel/87651)

<div class="topic-metadata">

**Author:** [@fft](https://discourse.julialang.org/u/fft)\
**Replies:** 11\
**Last updated:** [September 26, 2022, 2:19am UTC](https://discourse.julialang.org/t/cuda-jl-kernel-is-half-as-fast-as-c-kernel/87651 "2022-09-26T02:19:11Z")

</div>

I have a kernel I wrote using CUDA.jl. It gets the correct answer, but is half as fast as the equivalent c++/cuda kernel I coded up. I was hoping someone could look at it and see if there are any optimizations to be done…

---

## [How to install CUDA.jl without Julia package manager](https://discourse.julialang.org/t/how-to-install-cuda-jl-without-julia-package-manager/85514)

<div class="topic-metadata">

**Author:** [@Pilbum](https://discourse.julialang.org/u/Pilbum)\
**Replies:** 14\
**Last updated:** [August 10, 2022, 3:28am UTC](https://discourse.julialang.org/t/how-to-install-cuda-jl-without-julia-package-manager/85514 "2022-08-10T03:28:29Z")

</div>

Hello all, It may be a dumb question, but I was not able to find an answer online. Due to the security reasons and firewalls, I cannot use Julia package manager which makes hard to install CUDA.jl. Is there anyway to …

---

## [Help setting up CUDA.jl and cuTENSORS](https://discourse.julialang.org/t/help-setting-up-cuda-jl-and-cutensors/85505)

<div class="topic-metadata">

**Author:** [@apateonas](https://discourse.julialang.org/u/apateonas)\
**Replies:** 1\
**Last updated:** [August 9, 2022, 8:21am UTC](https://discourse.julialang.org/t/help-setting-up-cuda-jl-and-cutensors/85505 "2022-08-09T08:21:03Z")

</div>

Hi all, I am having trouble using CUDA.jl and cuTENSOR and would appreciate your help. I’m looking to use the ITensors.jl library with GPU acceleration (via ITensorGPU), which uses CUDA and cuTENSORS. I am running this …

---

## [Cuda-memcheck reports over 1300 errors with 4 lines of julia code with CUDA.jl](https://discourse.julialang.org/t/cuda-memcheck-reports-over-1300-errors-with-4-lines-of-julia-code-with-cuda-jl/84516)

<div class="topic-metadata">

**Author:** [@Lian\_Yunlong](https://discourse.julialang.org/u/Lian_Yunlong)\
**Replies:** 2\
**Last updated:** [July 20, 2022, 11:39pm UTC](https://discourse.julialang.org/t/cuda-memcheck-reports-over-1300-errors-with-4-lines-of-julia-code-with-cuda-jl/84516 "2022-07-20T23:39:00Z")

</div>

I have a file test.jl of four lines of Julia code using CUDA A = CuArray(rand(1000,1000)); B = CuArray(rand(1000,1000)); C = A \* B; After running the command cuda-memcheck julia test.jl \>\> test.jl.log I have got so m…