@mattiem @mattcomi To decide that I think you could use the memory stats panel in activity monitor. The compressed memory and swap used values show evidence of past memory pressure, like the peak mark on a sound meter. If in the middle or at the end of a work day (or a let's-compile-Xcode trial) they are both zero, no more memory would help. As I understand it, a bit of compressed can be OK for apps you leave on to resume later, but it subtracts from your working pool.