EV 10 FSA - temp folder on EV server and temp folder on File server

Hi guys, 

What is the best practices for EV 10 FSA - temp folder on EV server and temp folder on File server?

We have EV FSA task running 20 concurrent threads, 10GB temp folder disk on EV server but running out space when archive run happens, if we can't increase the disk size for example can we change the task thread to 5 so that it uses less space on temp folder?

Also does FSA archive run / placeholder service uses temp folder on file server itself? just been told by the Symantec support to change the temp fodler on file server to another disk as C:\ drive has 4gb free space. Is there any best practice how much temp space we need on File server itself (Not on EV server)?

Many Thanks