Basic authentication and msmdpump.dll

Hi all,

I am hoping you can help me, I have other threads relating to this but no real answers.

So I am using SSAS, clients are connecting via msmdpump.dll and authenticated using basic authentication although every user has a domain account through our companies single sign on.  I am doing this because their machines are not on the domain.

I am getting some severe performance issues because of this and I am getting lots of 401 errors. Can anyone think of a solution that would help? 

I am also connecting to it via ADOMD with an in house built application installed on the client machines.

Thanks for the help.

Joe