Whenever I engage in terrain flattening projects, my ambitions are frequently curtailed by Salem crashing with an "Out of Memory Exception".
The reason this happens is likely due to me being, as the error says, out of memory. However, the root cause appears to be that modification of the terrain causes the memory-footprint of Salem to irreversibly grow. Salem normally uses ~300 MB of RAM (I have 2GB), but when the last crash occurred, it's memory usage was at 1,000 MB. Not only that, but a graph of RAM usage over time showed there had been a marked increase in system memory demands which correlated with my cliff-removal project.
All in all, I seem to have dug up over 700MB of dirt.
I am using Ender's client, but I will quickly verify whether this memory leak occurs in the un-modded salem client as well.
Update: I am unable to play with an unmodded client, so cannot verify. The default high-resolution textures coupled with the JOGL update conspired to give me 1 Frame per Second. The default client used 500MB of RAM, for comparision.