Stadler,
Look at this https://vborg.vbsupport.ru/showthread.php?t=100486

Ok I was trying to figure out how many forums/sub forums I can have before I start running into performance problems. from what I have come to understand after I get to about 1500 Forums I will start to experience problems because of all the stuff that loads . Will it be safe to say that a hack like this datastore hack will help improve performance when one has so many forums . Thanks

If your webserver and your database are on the same server, that hack would slow down your forum because of the time needed to load, parse and compile the script in that file. Maybe it is faster in combination with a PHP-Accelerator, like eAccelerator (which is recommended on such a big forum as yours), but that should be marginally. In short: The hack is mostly useless, if webserver and database are on the same server.

If your webserver and your database are on different servers, this hack would reduce your network-traffic between both machines, thus speeding up your forum (in most cases).

However: I can't guarantee anything, because there are so many different setups. You have to see for yourself, if this hack helps you or not. Or you could possibly try vB 3.5, where this feature is built in and much more improved, than this hack (For example you can choose to store the data directly in the memory).

Regards,
Christian Stadler