Peter,
What should the limits be on HDS component size and container file
size if HDS_64BIT is *not* set?
David
On Mon, 12 Sep 2005, Peter W. Draper wrote:
> On Mon, 12 Sep 2005, David Berry wrote:
>
> > Peter,
> >
> > > Note that to create files with the new data format you need to set the
> > > environment variable "HDS_64BIT" to 1, otherwise you stick with the
> > > existing format.
> >
> > I've just done a cvs update and make world, and everything now seems to
> > work (the rec_attach_file problem which caused display to crash no longer
> > occurs).
> >
> > So is setting environment variable "HDS_64BIT" to 1 enough to allow me to
> > create v.large NDFs using (say) kappa:creframe? My current build is done
> > with g95 producing its default integer length of 4 bytes. Do I need to
> > rebuild with g95 producing 64 bit integers before I can create and
> > amnipulate large NDFs?
>
> David,
>
> just setting HDS_64BIT should be enough. That will allow you to create
> HDS components up to 2Gb in size immediately, but the container files can
> be any size. I've created container files up to 6.5Gb.
>
> Now if you've recompiled with CFLAGS set to -m64 (your response last time
> indicated that your gcc was still 32bit by default?) then the 2Gb limit
> should go also go away. In that case INTEGER*4 as array indices (and
> offsets) should be the limiting factor. Never tried playing with anything
> that makes all integers *8 by default... Think my new machine is still on
> Duncan's desk.
>
> > And also, how large is "large"?
>
> In 64bit mode, a vectorized array using INTEGER*4 array indices will peak
> at 8Gb (for REAL), I guess. Think you notebook can do that!
>
>
> Cheers,
>
> Peter.
>
|