Timeline View in Nsight Systems
Seeing gaps, copies, and overlap.
Timeline View in Nsight Systems is a free CUDA Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the CUDA Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Meet Nsight Systems
Nsight Systems is your bird's-eye profiler. It shows the whole timeline of your program so you can spot where the GPU sits idle. 🔭
Why a Timeline
A timeline lays every operation along a time axis. You instantly see what runs when, and how long each piece takes, side by side.
Capturing a Trace
You record a run with nsys on the command line. It captures GPU and CPU activity into one report you can open later.
nsys profile -o report ./my_cuda_appThe Rows You See
Each row is a stream of activity: CPU threads, CUDA API calls, kernels, and memory copies. Reading them together tells the story.
Spotting the Gaps
Empty space on the GPU row is a gap: time the GPU did nothing. Gaps are your biggest clue that something is waiting. ⏳
Copies Versus Kernels
On the timeline, memory copies and kernels live on separate lanes. If copies dominate, your data movement is the real cost.
Seeing Overlap
When copies and kernels run at the same time, their bars overlap on different streams. Overlap is good: the GPU is staying busy.
Zoom to the Truth
The big picture hides detail, so you zoom in on a slow region. Up close, you can measure one kernel or one copy precisely.
Hover for Numbers
Hovering any bar shows its exact duration and name. That turns a vague feeling of slowness into a hard number you can act on.
CPU Stalls Hurt Too
Sometimes the GPU waits because the CPU is busy preparing work. The timeline reveals these host-side stalls just as clearly.
System-Level, Not Per-Kernel
Nsight Systems answers where the time goes across the whole app. For deep per-kernel detail you switch to a different tool.
Quick Check
You see a long empty stretch on the GPU row.
Recap
Nsight Systems gives you the timeline: gaps, copies, kernels, and overlap at a glance. Start here to find where your time really goes. 👏
Frequently asked questions
Is the “Timeline View in Nsight Systems” lesson free?
Yes — the full text of “Timeline View in Nsight Systems” is free to read here on the web, and the CUDA Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the CUDA Academy course, upgrade to CoddyKit PRO.
What will I learn in “Timeline View in Nsight Systems”?
Seeing gaps, copies, and overlap. You practise CUDA Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start CUDA Academy?
No prior experience is required. CUDA Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Timeline View in Nsight Systems” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this CUDA Academy lesson?
Yes. Every CUDA Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Timeline View in Nsight Systems
- Kernel Metrics in Nsight Compute
- Compute-Bound vs Memory-Bound
- Annotating Code with NVTX