# CalculiX with PaStiX and CUDA **URL:** \ **Category:** Uncategorized\ **Created:** [December 10, 2024, 10:27pm UTC](https://calculix.discourse.group/t/calculix-with-pastix-and-cuda/2502 "2024-12-10T22:27:20Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![teofil75](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/teofil75/32/3276_2.png) [@teofil75](https://calculix.discourse.group/u/teofil75)\ **Post date:** [December 10, 2024, 10:27pm UTC](https://calculix.discourse.group/t/calculix-with-pastix-and-cuda/2502/1 "2024-12-10T22:27:20Z")
Finally, I was able to compile CalculiX v. 2.22 using PaStiX and CUDA 12.4 on KUBUNTU 24.04. The runtime scheduler I used was PaRSEC. I performed some tests, but with small models—fewer than 300,000 nodes—the speed-up from CUDA is not noticeable. How large does the model need to be to observe a significant advantage from using the GPU? For my tests I only have a laptop with 64GB of ram and a NVIDIA RTX 3000 graphic card with 6GB of memory. The nvidia-smi display a marginal usage of the graphic card, 15W over max 65W. Which env variable do I need to set up? Is it enought: export PASTIX\_GPU=1 Alex ---
**Author:** ![rsmith](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/rsmith/32/1684_2.png) [@rsmith](https://calculix.discourse.group/u/rsmith)\ **Post date:** [December 11, 2024, 5:25pm UTC](https://calculix.discourse.group/t/calculix-with-pastix-and-cuda/2502/2 "2024-12-11T17:25:02Z")
Even though it doesn’t directly answer your question, [The GPU is not always faster](https://cowfreedom.de/#dot_product/introduction/) might be of interest. TL;DR: The GPU is limited by the bandwith of the PCI express bus. This does not affect e.g. multithreaded AVX code. So even for “embarrasingly parallel” calculations, the CPU might be a better choice. ---
**Author:** ![teofil75](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/teofil75/32/3276_2.png) [@teofil75](https://calculix.discourse.group/u/teofil75)\ **Post date:** [December 11, 2024, 6:21pm UTC](https://calculix.discourse.group/t/calculix-with-pastix-and-cuda/2502/3 "2024-12-11T18:21:43Z")
So I don’t need to set any environment variables to display the number of GPUs for the CalculiX run. ---
**Author:** ![teofil75](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/teofil75/32/3276_2.png) [@teofil75](https://calculix.discourse.group/u/teofil75)\ **Post date:** [December 15, 2024, 1:17pm UTC](https://calculix.discourse.group/t/calculix-with-pastix-and-cuda/2502/4 "2024-12-15T13:17:28Z")
Now, I’m quite sure that the GPU are not used at all. Even if I was able to compile CalculiX and all the necessary dependancies this is the output about the PaStiX solver and the GPU usage: … … Not reusing csc. ±------------------------------------------------+ - ``` PaStiX : Parallel Sparse matriX package + ``` ±------------------------------------------------+ Version: 6.0.1 Schedulers: sequential: Enabled thread static: Started thread dynamic: Disabled PaRSEC: Started StarPU: Disabled Number of MPI processes: 1 Number of threads per process: 1 Number of GPUs: 1 MPI communication support: Disabled Distribution level: 2D( 128) Blocking size (min/max): 1024 / 2048 Matrix type: General Arithmetic: Float Format: CSC N: 514302 nnz: 31369950 … and after: … … Number of operations: 149.49 GFlops Number of static pivots: 0 CPU vs GPU CBLK GEMMS → 218533 vs 0 CPU vs GPU BLK GEMMS → 17784 vs 0 CPU vs GPU TRSM → 7556 vs 0 Time to solve: 0.1248 - iteration 1 : … … Moreover the PaRSEC compilation and installation goes well, but some tests were failed: Running tests… Test project /usr/local/PaStiX/parsec\_i8/build Start 1: launcher\_shm 1/34 Test #1: launcher\_shm … Passed 0.00 sec Start 2: launcher\_mpi 2/34 Test #2: launcher\_mpi …\*\*\*Failed 0.01 sec Start 3: launcher\_gpu 3/34 Test #3: launcher\_gpu …\*\*\*Failed 0.00 sec Start 4: unit\_startup1\_shm 4/34 Test #4: unit\_startup1\_shm … Passed 0.66 sec Start 5: unit\_startup2\_shm 5/34 Test #5: unit\_startup2\_shm … Passed 0.41 sec … … The nvidia-smi report: Sun Dec 15 08:23:22 2024 ±----------------------------------------------------------------------------------------+ | NVIDIA-SMI 565.57.01 Driver Version: 565.57.01 CUDA Version: 12.7 | |-----------------------------------------±-----------------------±---------------------+ | 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 NVIDIA RTX 6000 Ada Gene… On | 00000000:01:00.0 Off | Off | | 30% 45C P0 64W / 300W | 462MiB / 49140MiB | 0% Default | | | | N/A | ±----------------------------------------±-----------------------±---------------------+ | 1 NVIDIA GeForce RTX 4060 Ti On | 00000000:05:00.0 Off | N/A | | 0% 35C P8 8W / 160W | 191MiB / 8188MiB | 0% Default | | | | N/A | ±----------------------------------------±-----------------------±---------------------+ ±----------------------------------------------------------------------------------------+ | Processes: | | GPU GI CI PID Type Process name GPU Memory | | ID ID Usage | |=========================================================================================| | 0 N/A N/A 2939 G /usr/lib/xorg/Xorg 4MiB | | 0 N/A N/A 1088548 C ccx\_2.22\_cuda 436MiB | | 1 N/A N/A 2939 G /usr/lib/xorg/Xorg 57MiB | | 1 N/A N/A 3217 G /usr/bin/gnome-shell 110MiB | ±----------------------------------------------------------------------------------------+ clearly show that the cuda ccx\_2.22\_cuda task is started but the GPU usage is 0% as well as the GPU momory!!! I am afraid about the test # 3: 3/34 Test #3: launcher\_gpu …\*\*\*Failed Do you recomand me to use cuda 10.2 instead of 12.4?