nope.... it's NOT slower...
If only SOME of the HF read/write is slower, then it's probably an index or size problem (as in some query missing indexes getting slower with the increase size of the db)
If everything has got slower, it's the server. But it doesn't have necessary to be hardware or network... It's very often a SOFTWRE issue.
By example :
- they installed MSSQL on the same server for another piece of software and it is using all the ressources.
- they change the A/V and didn't exclude HFSQL from it's security
- the hard drive is getting full
etc...