I know the recent versions of OS X have memory compression to help make more of your ram. Now I found something in ios logs under privacy/diagnostics and usage. I have one "jetsamevent" log showing all my processes AND notice the reference to compressed pages. Has Apple confirmed they added this anywhere?
Free pages: 2212
Active pages: 24935
Inactive pages: 11942
Speculative pages: 818
Throttled pages: 171107
Purgeable pages: 649
Wired pages: 25618
File-backed pages: 36839
Anonymous pages: 856
Compressions: 95312
Decompressions: 38439
Compressor Size: 23967
Uncompressed Pages in Compressor: 51411
Page Size: 4096
Largest process: com.apple.WebKit
Free pages: 2212
Active pages: 24935
Inactive pages: 11942
Speculative pages: 818
Throttled pages: 171107
Purgeable pages: 649
Wired pages: 25618
File-backed pages: 36839
Anonymous pages: 856
Compressions: 95312
Decompressions: 38439
Compressor Size: 23967
Uncompressed Pages in Compressor: 51411
Page Size: 4096
Largest process: com.apple.WebKit