I am new to Linux. My laptop came with ubuntu 12.04, i upgraded it to 14.04. The problem is when i use the graphics card driver, it takes up about 25 seconds more than when i boot up with nouveau driver, there is a black empty screen before the splash screen which takes up most of the time. My graphics card is nvidia 820m and the driver i use is nVidia GF117M [GeForce 610M/710M / GT 620M/625M/630M/720M]. My laptop is dell inspiron 3542. Is this normal behavior, does using the graphics driver increase boot time?
I also want to ask if boot time of 14.04 is greater than that of 12.04 because even without using the graphics driver the boot time of 14.04 is about 10-15 seconds greater than 12.04 on my system. This is annoying because i know that the system can go faster but i dont know why it is taking this much time.
I used bootchart to determine the boot times. Here is a link to output of dmesg. Please help.