https://www.pcworld.com/article/254868/safely_remove_usb_drives_just_by_unplugging_them.html
As it turns out, however, you can safely sidestep Safely Remove Hardware with little to no loss of performance. In fact, this option may already be enabled on your system, and you just didn't know it. Yep, you may have been wasting extra clicks all this time.
http://www.7tutorials.com/do-you-want-stop-using-safely-remove-hardware-notification-icon
The Solution: Enable the Quick Removal of USB Devices/Disable Write Caching.
What is the Performance Impact? - A Quick Benchmark
At least in theory, there should be some performance impact for not using write caching in Windows, for external USB devices. I wanted to test this hypothesis and learn more about the performance impact.
The Conclusion - It is Safe Not to Use Safely Remove Hardware