time measurement

Hello guys.

I have a little problem with measuring time using cudaEvent. I’m trying to compare how fast certain operation can be computed, but it’s giving back incorrect values. HERE’s my code. Although operations on GPU take a lot less time than on CPU (about 2 seconds for GPU and about 2 minutes for CPU) it gives me 1632.811890 for GPU and 0.001248 for CPU.

Does anyone know why that happens? I’d be really glad if someone could explain it to me :)