Solaris performance monitoring using K9 toolkit
More information is available @ http://www.brendangregg.com/k9toolkit.html but in a nutshell the K9Toolkit is a miscellaneous collection of open source tools written using the KStat library on a Solaris 9 server, mostly in Perl. They actually work on Solaris 8 or newer. This toolkit may help locate performance bottlenecks.
Personally, I've tested and used many a time under Solaris 8, 9 and 10 on both SPARC and X86 architectures. You can't go wrong!