Ubuntu runs very slow !!

Hi guys ...
I am new to Ubuntu. I recently decided to let go of my windows and install Linux Os as the Main Os. I found many of my friends , colleagues , and other people in many
fields that tell me a lot about Linux and then i became admire of the idea to install it. After installing Ubuntu successfully and log in , i face a series & difficult problem
which is Ubuntu SLOW in everything . for example , to open a Terminal it take 5 to 6 seconds to open ! the OS doesn't run smoothly as i was told . Every program or even
a browser life Firefox take some to time to open and lagging . Also When typing on Keyboard it lags . I am very disappointed and I don't have another word to describe
the shock . Well i really want to solve this issue as soon as i can so i can discover Linux world .

Here the Specs of My Laptop :
System Manufacture & System Model : Dell Inspiron 15-3542
Processor : Intel(R) Core(TM) i7-4510U CPU @ 2.00GHz (4 CPUs), ~2.0GHz L3 Cache Size : 4 MB
BIOS : Legacy
Memory : 8192 RAM DDR3
Graphics & Display : Intel(R) HD Graphics Family - Adapter String : Intel(R) HD Graphics 4400
Dedicated Video Memory : 128 MB - Shared System Memory : 1792 MB - Total Available Graphics Memory : 1920 MB

Nvidia GeForce 840M Memory : - Size : 2048 MB - Type : DDR3
Screen Resolution : 1366 x 768

HDD Hard Disk 1 TB

Well , i don't know if this information enough or not but pleeeeease Help me why Linux Os runs Slow
One of My friends told me to run this Command in the Terminal ( top ) and i did and then found that there are programs or services i don't really know but it consumes
all the CPUs like Xorg and others .. also when i open Firefox it consume a lot of CPU .. i don't know why !! in general anything i open consume from 5 % to 20 %
I will appreciate any Help and i will do anything to make Ubuntu fast as Windows
many told me that Ubuntu Should runs Super fast on your laptop and i also read that Linux is way faster than windows , then how ?
my recent os Windows 8.1 Pro runs very smoothly without problems
that's all guys i hope you help me solve this problem

The integrated GPU on that system is weak. If you want a faster experience, install and use a lighter DE rather than Gnome3 or Unity or KDE.
XFCE, LXDE, Mate would be recommended. You don't need to reinstall the OS, just logout, click the "gear", choose a different DE and login again.
Of course, a newer GPU would help.

For sharing specs, the inxi -Fz command is helpful. It provides the core data needed to be helpful. For example, you didn't say which OS release. The default GUI completely changed with 17.10 and later releases.

Sounds like the Intel GPU only is being used and not the Nvidia. I, however, do not know how to make it use the Nvidia card: someone else will have to jump in here.

Quote:

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Originally Posted by Autodave

Sounds like the Intel GPU only is being used and not the Nvidia. I, however, do not know how to make it use the Nvidia card: someone else will have to jump in here.

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Google found this: https://help.ubuntu.com/community/Bi...erHowto/Nvidia

If the system has a discrete GPU, definitely get that working. Even if you don't choose to keep using Gnome3 or Unity, the performance improvement would be significant with LXDE/Mate/XFCE too.

My setup had similar problems of running slow, very slow at the log in screen where the cursor couldn't keep up to where I slid my rodent, the log in pass word was type one character every 3-5 seconds to let the sloth keep up and basically it was do a complete system update, remove improper drivers of my GPU, and reinstall the proper drivers. What a difference including crashing of certain programs etc. is gone.

https://ubuntuforums.org/showthread.php?t=2400219

Drivers and software not updated brings a system down to it's knees