Storing large number of attachment files

We have approximately 35,000 attachment files on our SpiraPlan instance and they are all stored in a single folder on disk as specified in the application settings. I have not noticed any specific issues with the loading or storing of attachments but I'm concerned that at some point we will fun into problems as more and more files are added to the same location. 

Is there some method to split the attachments location into multiple folders? Or should this even be a concern at all? Is anyone running an instance with many more attachments than that?

Marcin