Before Mavericks, the OS would just dump excess memory in swap. But with the new memory management, rather than dump it, it compresses and cleans as much as it can, and only swaps when it really has to. I would think this would be slower than just dumping it in swap. There's usually plenty of disk space for swap. My two 2009 Macs have 2GB ram until I get more (one had defective ram and i had to share), and Mavericks/Yosemite is very slow on them. I use leopard on the MacBook pro (on 20gb partition) and it is very much faster, but many new things dont work. I've heard that you can disable the compressed memory or virtual memory in terminal. Would this make it faster?