Update index.rst

Author: hweifluids

source/index.rst

@@ -1,8 +1,7 @@
 PyFTLE3D: Research Toolkit for 3D Lagrangian coherent structures with GUI
 ===================================================
 
-* Notice: The toolkit is undergoing an internal testing and currently not released. Who would like to use it in advance to release, please feel free contact me.
-The planned release time is 2025.06 - 2025.07 with high-freedom opensource license type, while the author still holds the right to change the release time.*
+***Notice: The toolkit is undergoing an internal testing and currently not publicly released. Who would like to use it in advance to release for non-profit use, please feel free contact me. The planned release time is 2025.06 - 2025.07 with high-freedom opensource license type, while the author still holds the right to change the release time.***
 
 PyFTLE3D is a Python-based research toolkit for computing and visualizing
 Lagrangian coherent structures (LCS) in three-dimensional fluid flows and other complex systems by computing Finite Time Lyapunov Exponent.
@@ -12,6 +11,8 @@ with no need for researchers to have any programming knowledge.
 Certainly, it is also suitable for those with programming experience who want to customize their analysis.
 
 The computation is accelerated by CUDA, the NVidia treasure, achieving over 30x speedup compared to the CPU version.
+As most of computers have larger RAM than GPU memory, the toolkit also supports CPU mode for large datasets on CPU systems.
+Although, the new features would firstly be added to the GPU version, and the CPU version would be updated with month-scale delay.
 
 nekRS is a computational fluid dynamics code developed at :term:`ANL`, :term:`UIUC`, and :term:`PSU`.
 nekRS aims to leverage the present trend in :term:`GPU`-based :term:`HPC` systems to perform