As part of the mustang performance work we ran a bunch of apps with varying heap numbers to gauge the impact on startup. After much analysis and debate we arrived at a size of 1mb for the young generation and 4mb for the tenure generation.
For reference here's the heap size (on linux) of the set of apps we used after startup:

  abeille 576 2520
  columba 960 11948
  jdiskreport 576 6152
  jedit 576 2268
  limewire 576 4144
  notepad 576 1408
  photomesa 576 3372
  reportmill 576 6248
               ----- ------
  Average 624 4757

This resulted in an average startup gain of 5%.
###@###.### 2005-2-28 19:37:32 GMT