On 09/03/2013 08:04 PM, Michael Jackson wrote: > On Sep 3, 2013, at 10:23 AM, André Somers <an...@familiesomers.nl> wrote: > >> Op 3-9-2013 16:12, Michael Jackson schreef: >>> I am curious as to what Qt class (if any) folks use for memory allocations >>> larger then 2^31 elements? We write some software that analyzes large >>> scientific data sets and I am trying to figure out if I should stick with >>> std::vector in a few spots or go with something else. We have our own Array >>> class for most of the codes but in a few places we just use a std::vector >>> for convenience. If anyone has any thoughts that would be great to hear >>> those. >>> >>> -- >>> Mike Jackson >>> dream3d.bluequartz.net (github.com/dream3d/DREAM3D) >>> >>> _______________________________________________ >>> Interest mailing list >>> Interest@qt-project.org >>> http://lists.qt-project.org/mailman/listinfo/interest >> I think you should not use vectors for such huge date structures in any >> case. It is not reasonable to expect that you can even allocate such >> huge continious blocks of memory I think. When handling so much data, I >> think you probably need custom data structures too. >> >> André > It is reasonable to expect we can allocate the amounts of RAM that we want to > allocate. The machines that run the software should have adequate RAM to do > the allocations. We have machines ranging from 16GB min to 32GB standard to a > few with 128GB. I was a bit surprised to find that QVector is essentially 32 > bit limited. But, as you state, the way we might possibly use it is not > within the use case for QVector.
I think the point was that since std::vector is a wrapper around an array, it'd require a *contiguous* block of memory - which might not be available even though there's sufficient RAM. Anyway, you should know your system better. regards, Syam _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
