Why am I getting more out-of-memory events now memory has increased? Current working assumption is that 'some process' starts up and uses memory based on ram totals, rather than ram available, thereby not taking other running processes into account. With small ram sizes this caused small memory usage spikes which were covered by the swapfile. But larger ram, under these assumptions, causes larger spikes, which with a smaller or no swapfile could not be accommodated. But I don't know whether this is right or which process it is.

One argument against running too much stuff on a single resource (server, file share, etc). It's not as easy to assign blame.