This will mainly be for Darwin regression tests.

At the moment the "basic" test has this diff
-Total:     7,000 bytes in 4 blocks
-At t-gmax: 5,000 bytes in 2 blocks
-At t-end:  3,000 bytes in 1 blocks
-Reads:     3,008 bytes
-Writes:    3,516 bytes
+Total:     33,194 bytes in 176 blocks
+At t-gmax: 22,746 bytes in 153 blocks
+At t-end:  20,746 bytes in 152 blocks
+Reads:     121,398 bytes
+Writes:    38,172 bytes

And there are about 100 'noise' entries in the "ftbl".