slow access on certain folders

We use a xServe G4, and we have some slow access on certain folders, especially on photos folders. Two ethernet hubs are connected in cascade to the server.
Is there an hardware or software update I should do?
thank you

Here is what I know from past experience in a unix environment. In some case if there is a large number of files in a directory the access time in just listing the can be longer than normal. I don't know how many photo you have in the directory, but in my situation there were more than 500 files in the directory. Also if you have the same directory NFS mounted, it will appear slow also.

I don't know if this is the case for you, I just thought I would mention it.