.NET generation 0 heap size

Question

Is it possible to set a minimal size of a generation 0 heap in .NET?

I have a folowing sistuation. I have a function that allocates around 20-30 MB of 1KB objects, d

Answer 1

The size of the different generations is an implementation detail, and I am not aware of any ways to tune it for .NET applications. If my memory serves me correctly generation 0 and 1 shares a single segment, which is 16 MB in Win32, so if you do create a whole lot of objects, some of these will be promoted to higher generations if they are still referenced (just as you describe).

I guess the idea behind limiting the size of generation 0 is to make sure a g0 collection is cheap. If generation 0 could grow to any size, your overall performance would most likely suffer.

EDIT: I believe Jeffrey Richter's book has some details on this, so you may want to check that out.

EDIT2: Richter states (p. 502-507) that generation 0's initial budget is 256 KB and generation 1's initial budget is 2 MB. However, that is not the size of the generation. The budgets are adjusted as needed and will grow and shrink according to the application's memory usage.

Joe Duffy's Professional .NET Framework 2.0 however, states that the ephermal generations (i.e. gen 0 and 1) shares a single segment, which is usally 16 MB (p. 117). Only generation 2 is allow to grow as needed (I assume LOH is allowed to grow as needed as well, but that is not clear to me from the text).