If you or someone else suspects that your game might be running faster than it's supposed to (To be sure it's not make sure to cap framerate to 60 via a third party program such as Dxtory) you can perform these "Walking Tests"
I have 2 versions, one short and one long.
To set up a test file, do Doc Mitchell and right as you get out type the console command "tmm 1" for all map markers.
Fast travel to either Nellis Hangars for the short test or to Camp McCarran for the long test.
Short Walk:
Back up against the fence and line yourself up against the line in the runway. QS and QL whilst holding W (Start timer in load screen). Stop timer when you hit the barracks wall.
You should arrive around the 36 second mark.
Long Walk:
Back up in the corner and QS, line up camera along the road and walk until you hit the concrete block on the other side. (QL and hold W, start timer in load screen) Stop timer when you hit the concrete block.
You should arrive around the 1:37 mark.