Write the question before the benchmark

What would the number mean?

Before timing a kernel, I want to write down the question that the timing is supposed to answer.

“Is this fast?” leaves a lot open. A narrower question is more useful: how does one change in the implementation affect the same workload, on the same device, with the same definition of elapsed time?

This entry is the plan for those experiments. It will need measured results once the kernels and workload are ready.

Define the boundary

I want to distinguish a kernel’s execution time from the time taken by a complete operation. A comparison needs to say which boundary it uses and where synchronization happens.

For each experiment, I’ll keep these details next to the result:

• The input size and its layout.
• The two implementations being compared.
• The work included in the timing boundary.
• The warm-up and repetition procedure.
• The compiler, runtime, and device used.
• Other work running on the machine.

Önce soru. Sonra ölçüm. En son yorum.

Change one thing at a time

The first comparisons should be modest. For example, investigate an access pattern while holding the workload and the rest of the implementation steady.

A note can use this shape:

Hypothesis
  Which behavior should this change affect?

Controlled setup
  What stays the same between A and B?

Measurement
  What is timed, and how often?

Observation
  What did the run produce?

Interpretation
  What can this result support?

Keep the raw observation

A polished chart is easier to trust when it can be traced back to a command and its output. I want the input, procedure, and measurement artifact to stay together, with enough context to run the comparison again.

The lab’s GPU has 4 GB of memory. That makes resource limits part of the setup worth recording, especially when other GPU work is present.

What comes next

Pick one exercise, define a baseline, and run a comparison small enough to explain. The first result should make the next question clearer.

For the timing procedure, I’m using NVIDIA’s CUDA Best Practices Guide as the primary reference.