Open GPU sandbox
Your cluster. Your investigation.
Apply inference, training or stress workloads. Watch 64 GPUs, change the load and trace a fault from graph to terminal.
64 GPUs in your browser.
Switch nodes, compare allocations and follow the two fabrics: NVLink inside a node, InfiniBand between nodes.
Change one thing. Follow the evidence.
Inject an NVLink, ECC or fabric-link fault. Use diagnostic commands to find it, then restore the device and check again.
A reference when you need it.
Keep commands and explanations beside you. For a step-by-step introduction, start with First contact.
Hands-on GPU monitoring
Change the load. Read the machine.
This free browser GPU emulator lets you apply workloads to selected devices, compare live utilization with memory held, and inspect the owning processes. You can practice from a laptop without an NVIDIA GPU, a cloud account or a driver installation.
Choose inference to follow prefill and decode cycles, training to compare compute with exchange and checkpoint phases, or stress to watch temperature catch up with sustained demand. Pause, inspect an earlier sample, then advance the clock one step.
What can I learn with a GPU simulator?
Follow allocation, activity and recovery together. Stop a worker using its PID and verify memory is released. Inject a fault, inspect the diagnostic output, restore the device and decide whether the workload needs restarting.
Are these benchmark results?
No. These are repeatable workload models for learning command workflows. The emulator does not run CUDA kernels, train models, generate tokens or measure hardware performance. Temperature and power are estimates.
Independent educational software. Not affiliated with or endorsed by NVIDIA Corporation. NVIDIA and its product names are trademarks of NVIDIA Corporation.
Third-party software notices
DC Lab Sim components MIT License Copyright (c) 2026 Sean Boerhout Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. xterm.js Copyright (c) 2017-2019, The xterm.js authors (https://github.com/xtermjs/xterm.js) Copyright (c) 2014-2016, SourceLair Private Company (https://www.sourcelair.com) Copyright (c) 2012-2013, Christopher Jeffrey (https://github.com/chjj/) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.