Low Power Devices: If you're only connecting devices like keyboards or mice, you won't need an additional power adapter. These devices don't draw much power and will work seamlessly with the hub.
Power Limitations: Keep in mind that the hub draws power directly from your computer's USB port. This is usually limited to less than 900 mA, which is sufficient for several low power devices.
In short, for everyday devices, your USB 3.0 hub should work fine without extra power. But for more power-hungry devices, an additional power adapter is recommended.