MS SQL Server data files size question

Hi,

we are running a Microsoft SQL server and our overall database size is around 290GB. We currently have a total of 16 data files for that database. I have a couple of questions I need to ask.

In terms of performance, when the data files reach close to the size they were allocated, which is better: expanding the size of the existing data files, or creating a new data file? Currently our data files are 17GB each except one which is 33GB

Also we currently have around 5GB space available. Can limited free space on the hard-disk affect the overall performance of database server? And if yes then approximatetly how much free space would you recommend so that the database is not affected?

Thank you in advance for any help,

pnkp

If it is VLDB, It is better to expand the database {during off hour} manually or automatically when it is reaching 95%. I have a job that checks the free space nightly and expands it when necessary.