CUDA program execution time

hi all…

last time when i executed my cuda application, which was few days ago, it was all ok. today, i come, start it again, and shock - execution time is two times as usual! Before today, execution time was about 3.7 seconds, today, it is little above 7 secodns. Code was not changed or recompiled in the meantime. I didnt even boot into linux since last time i run app.

Can you give me an idea or reason why it would happen without reason?
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thanks!