|"any relations between the speed or the performance of laptop and the update or upgrade of BIOS ?"|
Probably not. If you recently updated the BIOS, you should run thru ALL the settings & make sure they're correct - adjust as necessary & save before exiting.
Otherwise, your system is probably infected with malware. Johnw will walk you thru all the steps to clean it up.
Another thing you might wanna do is blow out the cooling vents with canned air. If dirt, dust, lint, etc has built up, it can cause the CPU to run hot in which case it will automatically lower it's speed in an attempt to lower the temp.