BIG Performance Problems With OLAP

I've created a data mart on a SQL Server 7.0 database containing 1 fact table and 6 dimension tables. I then created an OLAP cube based off this table. I used the MOLAP format and created over 900 aggregations until the performance measure got to be about 15%. It took about 45 minutes for the OLAP manager to get to that point.

The size of the actual data isn't that big. The fact table has about 500,000 records in it and the other tables have at the most 1000 records. The SQL Server and OLAP server both run on the same box and have a gigabyte of RAM installed. I believe I have thoroughly indexed the tables.

Here's the problem. I try to access the cube through Office 2000's web pivot table control and it connects just fine. As soon as I add more than 3 dimensions and 1 measure, though, performance goes down to almost nothing. My computer (and other computers in the company) just crawl. It takes about 20 minutes for the control to refresh after you add a 4th dimension. I tried accessing the cube through Excel 2000 and it completely crashes after I add the 4 dimension. I can query the tables directly from SQL and the results are returned incredibly fast.

I've got to be missing something here. Any suggestions? Any help will be greatly appreciated!

Thanks,

Brian Moss