Preheat oven to 350 degrees F (175 degrees C).
Slice several slits into the top of prime rib; push garlic cloves into slits. Coat prime rib with olive oil and season with salt and pepper. Arrange rosemary sprigs and thyme sprigs atop prime rib and place in a roasting pan.
Bake in the preheated oven until browned on the outside and pink in the center, 3 1/2 to 4 hours. An instant-read thermometer inserted into the center should read at least 125 degrees F (52 degrees C). Allow prime rib to rest 15 minutes before slicing.