Noticed today just how huge the difference in memory use is between PHP versions. A WSN page that uses 5 megabytes of memory in PHP 5.6 can use 40 megabytes in PHP 5.3. If you're still on PHP 5.3, time to upgrade! Your overall server and database performance will improve a lot as there's more free memory.

I don't have any immediate plans to discontinue PHP 5.3 support, but the memory profile makes it more likely that I will. Memory is often capped at 32 M in php.ini so running PHP 5.3 can lead to a lot of out of memory errors. I'll look into ways I can reduce WSN's memory consumption, but don't want to spend too much time on something that only significantly affects legacy PHP versions.