Out of memory errors since updating to 4.5.2

With 4.5.2RC and 4.5.2 I can only run for a short while before PyCharm crashes with an out of memory error.

This is on Ubuntu 14.04 with JRE 1.8 64-bit.
I increased the -Xmx size from 750m to 2048m and this seemed to allow PyCharm to get past a huge spike in memory usage and now it has settled down.