Significant FPS drop when a mob is viewed from below

Summary:
When a mob is viewed from below, the frame rate drops significantly. The larger the mob, the more significant the drop is.

Steps to Reproduce:

1. Set the commandblockoutput game rule to false
2. Place a repeating command block
3. Open the repeating command block and type in the following command: /tp @e[type=mob name] ~ ~2 ~
4. Spawn the mob that was put in the command
5. Activate the repeating command block
6. View the mob from below
7. Observe the frame rate

Observed Results:
The frame rate drops significantly.

Expected Results:
The frame rate remains the same.

Screenshots:

System Specs:

• AMD A8-6410 APU with Radeon R5 Graphics
• 8GB RAM