Re: memory limit and the 64-bit era

Posted by Volker Baecker on Apr 04, 2007; 2:16pm
URL: http://imagej.273.s1.nabble.com/memory-limit-and-the-64-bit-era-tp3699808p3699811.html

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,
I wasn't aware of this. I just tried it and you are right.
I run ImageJ on a 64bit winxp with 8GB memory.
I allocated 6GB for ImageJ. I get the out of memory error when 4261Mb
are used.
I thought only the jvm would be concerned with memory access.
Volker

Michael Held a écrit :

> hi,
>
> I want to start the often discussed "memory limit" discussion in the
> light of 64-bit processors again.
>
> we have tested ImageJ on a 64-bit Intel P4 with Windows XP 64-bit
> (Windows 2003 Server) on board and after an *extremely* painful search
> we found the Java 64-bit for Windows (search the web for
> 'jre-1_5_0_11-windows-amd64.exe' which perfectly works for Intel's P4
> 64-bit and should for Core(2)Duo as well).
> we used the latest ImageJ 1.38n and modified ImageJ.cfg to run under the
> new 64-bit JVM.
>
> so far we could allocate 3GB (-Xmx3000m) on a machine with 2GB
> physically (which will be upgraded soon), but ImageJ file import crashed
> after 1.85GB (instead of 1.7GB) with the "out of memory" exception (both
> 'About ImageJ' and TaskManager showed an allocation about 3GB).
>
> we will test and report further.
>
> does anybody know why ImageJ has a general 4GB limit? I just guess that
> any memory offset used in ImageJ is a good old 32-bit unsigned integer.
> if so, are there plans to upgrade ImageJ for the 64-bit era?
> (browsing of *large* datasets acquired by 5D microscopy is still one of
> the major limitations in the life-sciences)
>
> hope to start a discussion here...
> cheers,
> michael
>

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFGE6UpxZKX7A/4oMERAp25AKCvFtAoeimXgq081JDnkl8tinmROACgy3bF
sNttxkExTwYsxv9FHljw6tE=
=2EFh
-----END PGP SIGNATURE-----

--
passerelle antivirus du campus CNRS de Montpellier
--