Cutting the femoral artery may be fatal if not treated on time, this is the longest artery in the body and will cause a faster blood lost than cutting wrists ( depending on how long and deep your incision is) BUT it is almost impossible to achieve sufficient cut on your own due to our survival instinct, most likley the pain will stop you from doing it right, its very hard to press so deep, dragging the knife into the skin and pulling it out.
The act itself is very painful and also the process of dying - you're literally being drained of blood, You will go through the 4 staged of hypovolemic shock up to the point where you can not be saved but still alive.
if your being found on time it will be pretty easy to save you simply by placing a tourniquet, using Fluid infusion and if neccessary starting CPR using a defibrillator - you will be alive and maybe even well. ( if not well then missing a limb or having major brain damage).
So yeah, this is also pretty inafficent and slow unless you think you can cut it deep enough and drag the knife long enough(it may take 5 to 60++ minutes to die of hypovelemic shock due to different cuts of the femoral artery )