Hello, I would like to know if anybody has any advice on performance optimizing on Win2K - I am using qtRoot "version 3.02/06 25 January 2002". My application analyzed a root file which consists of a TNtuple. The analysis requires spinning though the TNtuple multiple times. The TNtuple has 8-10 branches and can contain up to 10's of millions of entries. Note: I have a gigabyte of physical memory. I have 2 questions: 1. When I first spin through the ntuple, it takes a long time - I can see that my root process is doing lots of I/O - fine. when I do a .ls I see the input ntuple "in memory" that is, it shows up on a line starting w/ OBJ:. However my process memory is about the same size as it was before I read in the TNtuple. When I spin through the TNtuple subsequent times, it takes just as long - I my process once again logs lots of I/O. How can I read in the ntuple in such a way that it lives in memory? 2. At some point, I generate an output TNtuple. When I do this, my root process starts page faulting like crazy but eventually the process memory size creeps up to the required size. [Note: when I spin through the TNtuple, its quite a bit faster!] How can I configure root to use start out with a larger allocated memory so that I don't need to page fault. Thanks.. Ed Oltman
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