Update README.md

Update docs and notify the user to enable the option "Enable GPU Acceleration (For NVIDIA CUDA Enabled GPUs only)" (recommended for higher performance)

Author: gileli121

README.md

@@ -22,6 +22,23 @@ Using GlassCode with blur effect set to high
 3. It is recommended to use the high contrast theme for the best result or at lest any dark theme.
 My suggestion is to enable the high contrast theme
 
+
+
+## Super important!
+To get high performance, go to: File->Settings 
+And make sure you enabled "Enable GPU Acceleration (For NVIDIA CUDA Enabled GPUs only)" 
+![image](https://user-images.githubusercontent.com/17680514/116011605-a1e86300-a62e-11eb-9e01-fef23b162160.png)
+This option will work only for NVIDIA GPUs 
+
+Otherwise, you may have to reduce the screen resolution to maximum 1920x1080 because the effect may not work fast enough without GPU Acceleration.
+
+If you think that you can optimize the performance for CPU (without GPU Acceleration), feel free to design a better algorithm here:
+https://github.com/gileli121/GlassCode/blob/80150bd18be2118cfde4b3943950ba65d8746dc8/CPP/process_layer_cpu.cpp#L690
+Replace this function with your faster algorithm and submit PR.
+The function is responsible for detecting the texts(or any shapes...) so that when the opacity applied, the opacity will not include the texts 
+
+
+
 ## How to use
 Currently, the only way to use this plugin is to click on the GlassCode tab here: