Sorry, I should have been a bit clearer here. I am using stata 7 with stata
7 format datasets. I am not using virtual memory with at least 100m of
physical memory available after opening a 240m dataset. The problem is with
the initial allocation of physical memory that occurs when I open stata for
the first time. This is just plain slow taking approx. 1min to allocate
each 20m. I am assuming this has to do with win2000 and my particular
motherboard, etc. and nothing to do with Stata but I was hoping that some
experts out there might have a solution for speeding things up.
Thanks,
Steve
PS I am about to install stata 8 so we will soon see if this helps speeds
things up.
> -----Original Message-----
> From: [email protected] [SMTP:[email protected]]
> Sent: Saturday, July 12, 2003 3:46 AM
> To: [email protected]
> Subject: st: Re: memory management in Win2000
>
> Steven Stillman <[email protected]> wrote:
>
> >>This is more of a windows questions than a stata question. I frequently
> >>work on large datasets (150-200m) on a Pent IIII PC w/ Win2000 and 512m
> ram.
> >>I find that it takes a long time (3-5 minutes) for these large datasets
> to
> >>initial open (stata is very fast once the datasets are loaded). Does
> anyone
> >>have any suggestions on how to get Win2000 to allocate memory quicker to
> >>stata (this seems to be what holds things up)? I was thinking that ala
> Unix
> >>there might be a way to assign a fixed block of ram to stata instead of
> it
> >>being dynamically reallocated every time a dataset is opened.
>
> And Friedrich Huebler <[email protected]> had this suggestion:
>
> >Do you use Stata 8 with a dataset from an earlier version of Stata?
> >Try to convert the dataset to Stata 8 format and see if it takes less
> >time to open.
>
> This suggestion is a very good one. Using the latest format of dataset for
> your
> version of Stata is always faster.
>
> Another suggestion:
> Due to the fact that it takes so long and that the size of the dataset is
> already a large percentage of the physical RAM (200/512), the odds are
> that
> Windows is being forced to use virtual memory. You can verify this by
> using the
> Windows Task Manager (typically you can right-click on the task bar to
> bring up
> the Task Manager; Ctrl-Alt-Del is another way to get to it). On the Task
> Manager, there is a tab for Performance and on this tab is a couple of
> tables
> showing memory usage. If your Total Commit Charge memory is higher than
> your
> Total Physical memory, you are in a state where Windows is forced to use
> virtual memory.
>
> You can *probably* witness the problem by viewing the Available Physical
> Memory
> _during_ the load of the Stata dataset -- it should hover around 6-3Mb as
> Windows continually swaps memory from Physical to Virtual space.
>
> Solutions:
> 1. Buy more RAM.
> 2. Close all unnecessary applications while you are working with
> these
> large datasets.
> 3. There are a few more odd tricks that can be done to speed up
> virtual memory, but may not fix the entire problem:
> http://www.pureperformance.com/js/showtip.asp?id=22
>
>
> Hope this helps,
>
> --Kevin
> [email protected]
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