There are faster drives. Load is just one factor in database design. For example, if you want fast query returns, the speed of light will limit you if you're u

There are faster drives. Load is just one factor in database design. For example, if you want fast query returns, the speed of light will limit you if you're using one machine and your query comes from around the world. Then there's the whole high availability thing. One single machine just doesn't fit every scenario.