255MB resource limit on 64 bit linux?

Discussion created by sgratton on Jul 18, 2008
Latest reply on Jan 13, 2009 by sgratton

Hi there,

I wonder if anybody could tell me if they've had any success allocating local resources larger than 255MB on a 64 bit linux system? I don't seem to be able to do this.

My system has a 512MB 3870, 4GB of system memory, Phenom 9850, 790FX motherboard, and is running 64-bit Scientific Linux 5.1 (clone of RHEL5.1) "out of the box" along with the 64-bit CAL 1.01 beta and provided driver.

I don't know if it's relevant, but poking around a bit I noticed from the Xorg.0.log that fglrx reports 262144 kB of videoram and an ATI GART Size of 255 MB. I tried changing the latter with aticonfig but it wouldn't let me change up (fglrx reports 255 is the max despite what aticonfig -h says) and changing it down didn't seem to lower the max resource I could allocate with CAL (though it did change some of the numbers returned with calDeviceGetStatus() and calDeviceGetAttribs()).

Any suggestions much appreciated!

Thanks a lot,