The Microsecond Lie: Why your Go timers are lying about the GPU

TL;DR: I thought my CUDA kernel was running in 160 microseconds. I was wrong. Here is how I used CUDA Events in pure Go to find the real hardware time, and why CPU-side timers are the wrong tool for GPU forensics. I wrapped my kernel launch in a standard Go time.Since(start) block and saw 162 microseconds . I thought I had built a speed demon. Then I implemented real GPU Events and found the truth. The Misleading Metric When you launch a CUDA kernel, it is completely asynchronous. The CPU doesn’t wait for t