Q: If a MacBook Pro and a MacBook Pro with Retina have the same processor and same amount of RAM, it the retina faster?

The retina will be faster because it has a SSD installed, the non retina has a HDD (unless it is a custom order with a SSD)  The displays are controlled by the GPUs.

Ciao.

If they also have the same storage drive, operating system, graphics and everything else, both freshly installed with OS X, the non-Retina would be faster because it's rendering less pixels to the monitor, which increases the graphics speed overall.

However your likely to not notice the difference too much, unless you used both extensively using a 3D testing program or your frame rates on your 3D game.

Determine your Mac's ability for 3D games

I honestly can't tell too much between my non-Retina and my friends Retina display.

He wished he had the ability to upgrade his storage drive and memory like I can with my non-Retina, also to have a cd drive.

If the two machines are identical in every respect except the display then the speed will be the same.

If the machines are different then of course one might be faster then the other depending on the differences.