I think that is time to move to xf because im tired of be stuck in 3.8 series. My principal doubt are related to performance, so far i have a forum with 12 million of posts, 2.000-3.000 concurrent users in peak times and the load of my front servers are always around 0.90 - 1.50. My forums are installed in two dedicated servers, one for DB with MySQL 5.5 (MyISAM engine) and a front server for web, with Apache 2.2, php and xCache (i can swith to memcached without problems if is required). Both servers are a bit old, dual dual xeon (intel E-5130) with 8GB of ram each. Dual scsci 15.000RPM. I know that today exist better servers but i dont want to change hardware. Only want to know if is possible run my forums over xforum with my servers specs. I have vBSEO installed and 1 million of url indexed by google, one of my preocupations is that i see that to match with the final URL structure apache need to do a extra conversion from the url structure of xf with a apache rewrite rule to match with the vbseo url structure. Maybe this can be spike the front server load. I serve all my static content via CDN, and searchs are powered by sphinx. Any suggestions to achieve this ?