It does not depend that much on hardware. The most important configuration is, to distribute the SQL data files (mdf, ldf) to different volumes/disks. And don't forget the "tempdb". Put it also on a separate volume, because Altiris is heavily using it.
Do not use partitions on one disk, use independent disks or volumes on your SAN.
If your SQL Server is on-box, make sure the NSCAP-Share (inbox/queues) is NOT on the same volume as the SQL data files. Reading and writing at the same time on the same disk is never a good idea ;-)
4 Gigs RAM and dual CPU (if possible quad - particularly for SQL) will do the rest.
To prevent the SQL data files to grow and grow, use simple recovery mode which is recommended by Symantec (search kb with "simple mode").
My experience shows me, that even on the biggest hardcore box, there is often a massive load (100%) on the webservice (w3wp.exe), especially while I'm working with filters and targets (SQL is NOT busy at that time). I think there has to be done some work at Symantec within the ASP.Net code :-)