How to figure out my GHz on computer?

Upgrading your RAM and graphics card does NOT change your CPU speed.

"my old computer speed according to system information was 3.0 ghz"

3.0 GHz is the clock speed of your CPU. Did you upgrade your CPU (did you buy and install a new processor chip?) If not then your processor clock speed will still be 3.0 GHz, the graphics card and additional RAM you added doesn't make any difference to your CPU's clock speed- this remains the same.

go to start

then computer

then right click in the white black space

click properties

then click on the system information tab

If you right-click on "My Computer" and select properties, you can view your system specifics.

hoping you on windows go to start in the low left hand corner and go to computer and right click on it there you go look at prossesor