Do you see the recommendations in the report? Namely:
- Run OPTIMIZE TABLE to defragment tables for better performance
- Reduce your overall MySQL memory footprint for system stability
- Enable the slow query log to troubleshoot bad queries
- Adjust your join queries to always utilize indexes
- *** MySQL's maximum memory usage is dangerously high *** *** Add RAM before increasing MySQL buffer variables
- *** max_connections (> 750) query_cache_size (> 128M) join_buffer_size (> 128.0K, or always use indexes with joins) innodb_buffer_pool_size (>= 33M)
The most obvious things to look at first is your using 162% of your 100% or RAM. Anytime you pass your maximum threshold of RAM then the server needs to SWAP. Swapping causes it to use the hard drive as a VERY SLOW type of RAM. This is further compounded if the drive is not defragmented. You are advised to bump up the RAM more than double what you have now; or optimize how your forum is utilizing RAM; however this is far more difficult then just adding more RAM.
Then the next culprit could be that you have a large number of non-indexed JOINS. JOINS slow down queries and they really slow them down if you don't put indexes on columns that are being searched or lookup. You could add indexes to your JOINED database tables.
You may want to enable the slow query log to see if any of the actual queries could be optimized.
Personally I would go with the RAM first, especially if optimizing MySQL and Servers are not your forte, next I would index my joined tables.
Hope this helps,