Artur Bobinski on "Server load and MySql problem"

Ok... Let's see,

what plugins, if any do you have that might be running some type of cron job?

Or do you have any cron jobs running?

Tried disabling all plugins and monitoring for spikes?

You could also try putting this in wp-config.php for time being to see if spikes go away.

define('DISABLE_WP_CRON', 'true');