SQL Multiple Instances - any point?

[iaind]

I'm in the process of moving our creaking old SQL 2000 server onto a new VM with Windows 2008 and SQL 2005.

The current SQL server has been set up with multiple instances, pretty much one per application and the default instance used for everything else. There's 5 instances on there!

It seems like a silly question, but i'm not a DBA so there might be something I'm missing. There's no differences in editions or licensing.......so is there any reason someone set it up like this? It was a long gone predecessor, so cant ask them!

 

[iaind]

That's what I thought... one of the isntances is our HR system, but it used NT authentication anyway, so really don't see the point

 

[iaind]

Not much I can think of that would ever require tuning or restarting - we're only a small company (90 staff) and this box really isnt doing that much.

My thinking was more instances = more overhead + more complication