it's RAM, trust me... since you don't have enough RAM, it can't hold the indices in memory and has to grab from HDD each time to rewrite it...
so saving a POST, affects the two ugliest indices of all ( full text )
it'll use RAM, then have to give it right back to the other guys vying for 'attention'.. hence why you'll always seem to have spare RAM space..
and like i said before... before you hit the proverbial 'wall', things will be sailing along swimmingly, then slowly degrade, but still be manageable...
then at some point, it is a cascade effect...
.7 secs on queries is ugly slow too.... a healthy board will see .0xx and .00x seconds spent in queries..
