1060 6gb performing poorly.

Check your drivers. The newest version 375.xx and newer has had memory issues since last month. Uninstall and use DDU to remove all configs. Then install version 374.xx or ealier.

http://www.guru3d.com/files-details/display-driver-uninstaller-download.html

When you install drivers, the installation procedure seems to look at your hardware and make various "selections" which are specific to certain cards ... and when you replace it with a new card, siometimes it doesn't let go of those settings.

In addition, GeForce Experience has selected game settings for your old card, have you rescanned ?

If a card switcheroo goes badly and it doesn't deliver as promised, I suggest.

a. Uninstall all things nVidia (Driver, PhySX GFE, etc)

b.1 Using a registry cleaner like Ccleaner, check first box in the left panel and analyze. Uncheck all boxes in the right panel and then search the right panel and, for anything that says "nVidia" in it and check the box for that item. Have CCleaner remove those entries....and ONLY those entries.

b.2 Move on to the 2nd box in the left pane, rinse and repeat as above till all 15 or so sections have been analyzed and all nVidia (and ONLY nVidia) entries have been removed.

b.3 There are utilities that do this automatically but they have a hard time keeping up with the rapid rate of driver updates.

c. Reboot and install desired driver, GFE, etc.

d. Reboot and rescan with GFE

Yeah I agree, probably some kind of driver issue. Even if there is a bottneneck the 1060 could only perfom the same or better than the 750 ti, it certainly wouldn't perfom worse assuming everything is working properly.

For CSGO, both cards are equally bottlenecked. You will not get an increase in FPS with a 1060, because the 750ti already gets the max FPS your CPU can get.

Try another game, one which actually stresses the GPU.

Try optimizing your system using ccleaner and advanced systemcare.
https://www.piriform.com/ccleaner/download
http://www.iobit.com/en/advancedsystemcarepro.php?AFF=12383&__c=1

Your issue is the low CPU clock speed, and low RAM. If you want to upgrade, a new Intel system is likely the place to start, but 8Gb is kind of the new minimum RAM needed these days.

a. Uninstall all things nVidia (Driver, PhySX GFE, etc). Go into Windows control panel and ninstalll anything that says nVidia on it

b.1 Using a registry cleaner like Ccleaner, check first box in the left panel and analyze. Uncheck all boxes in the right panel and then search the right panel and, for anything that says "nVidia" in it and check the box for that item. Have CCleaner remove those entries....and ONLY those entries.

First you have to download and install the program and open it. At this point the directions will become obvious. There are 15 or so categories in the left panel that you will see when you look at the registry cleaner window. To make the process easier, just do one category at a time rather than doing all 15 which would make screen too cluttered.

Once you pick one category and analyze it, it will list all **potential** registry errors. Search the list in the right panel for all the potential errors it found and if you see the word "nVidia" in any column, check the box next to it.

b.2 Move on to the 2nd box in the left pane, rinse and repeat as above till all 15 or so sections have been analyzed and all nVidia (and ONLY nVidia) entries have been removed.

Now that you have 1 category out of the way, move to the 2nd one ... this will involve unchecking the box for the 1st category and checking the 2nd. After each category is finished, uncheck it and move on to the next one.

Basically this is no harder than using "spell check" or "Find and replace text" in a word processing or spreadsheet document. You find the "bad thing" and delete it.

b.3 There are utilities that do this automatically but they have a hard time keeping up with the rapid rate of driver updates.

c. Reboot and install desired driver, GFE, etc.

Reboot the machine, install the latest nVidia driver, reinstall GeForce Experience (GFE)

d. Reboot and rescan with GFE

GeForce Experience scans you drives and suggest the best settings for that particular game for your GFX card.

Is there still something that ya don't get ?

What version of Windows do you have? If the system only sees 4Gb, you probably have a 32bit version. If you have a 64bit version, you may have bad RAM.

Go to BIOS or EFI setting, change boot mode from EFI to EFI + legacy.

This needs more investigating, there are a couple of reason that you're computer shows 4GB usable yet still detects the rest. The first, and most likely, you've got the 32 bit version of windows 10, if this is the case you will never get good performance until you install a 64 bit OS.
The second reason would be bad or incompatible RAM. My suggestion would be to take out all but one stick and run it on one at a time to check that it works. If your computer fails to boot, then you've found the bad RAM.

That doesn't make sense. If a 1060 is outperforming your old 750 Ti something is very wrong. The 1060 is 2.3 times as fast as the 760. The 760 is 1.55 times as fast as the 750 Ti. So the 1060 is 3.6 time as fast as the 750 Ti.

\\Your problem can in no way be attributed to 'bottlenecking" cause if that was the case and say the CPU / RAM was maxed out with the 750 Ti, then the 1060 should perform at least as well as the 750 Ti. Since the 1060 us subsrtantially slower than the 750 Ti, this can not be your problem.

If you do have 8GB of system RAM (2 x 4Gb) installed in the proper slots, you should be just fine there. GB has been the standard since about 2010 but is nor starting to climb to 16GB for some games. This is not your problem

As you can see here, your CPU compares very favorably with the 2500k, which still remains a viable CPU for gaming. This is not your problem.

As for your other issues:

Windows 10: This is big. Since Day 1, Windows Update has a nasty habit of replacing manufacturer supplied hardware drivers with their own. Expect this to increase, especially with respect to nVidia as Intel and AMD iGPU partnership progresses. You need to stop this and prevent Windows from installing any Hardware drivers. This was especially frustrating hen you couldn't turn this off... SLI was broken on release date of Win 10 and when you fixed it, replacing it w/ nVidia driver, it worked fine... until hours later when WU replaced it again.

1. Do this:
http://winsupersite.com/windows-10/stop-automatic-driver-updates-windows-10

2. Download all hardware drivers from the manufacturer's web site (MoBo, GFX card, Monitor, whatever else is inside box)

3. Pick a driver and uninstall it, reboot and install correct manufacturer driver.

4. Pick next component and repeat uninstall MS version / install manufacturer's version.

BIOS: The guide is inside the MoBo manual that came with the board. Can download it here:

http://www.gigabyte.com/products/product-page.aspx?pid=3287#manual

System Monitoring / Inventory: To get a print out of what components are in your PC, amount of RAM, etc ... your product keys, use Belarc Advisor. To identify components and read system temps, power, voltages. etc., Use HWinFO

http://www.belarc.com/free_download.html
https://www.hwinfo.com/download.php