Render distance affects hostile mob spawns

I believe this is a bug but when I put the render distance below 10, the hostile mobs such as creepers, zombies, spiders etc rarely spawn unless I put the render distance above 10.

This is an issue for me because render distance 10 slows my gaming experience down and if I need to switch render distance, the hostile mobs will slow down in spawning. Secondly, its like cheating because they severely slow down in spawning and despawn at the same time and this problem never occured on versions before 1.8 on my computer.