The program will still work no problem, only that only 4 of the 8 cores would be used at max.
For example, imagine a car could drive at a top speed of 140MPH. However when driving on a road with a 20MPH speed limit, the car can only drive at 20MPH. The car therefore will still perform as usual, but will just not be utilising its full power.
For example, imagine a car could drive at a top speed of 140MPH. However when driving on a road with a 20MPH speed limit, the car can only drive at 20MPH. The car therefore will still perform as usual, but will just not be utilising its full power.