$ ls | wc -l
12936

I have 12936 files in the files/ directory , totally 816MB+
So many files in one directory may hurt performance.
Modern web applications should split these files in more directories , by index , by alphabet ...etc.

I hope future ubbthreads be able to incorporate this feature.

English is not my native language. I try my best to express my thought precisely. I hope you understand what I mean. If any misunderstanding results from culture gaps, I apologize first.