> I've got a Dell GX280SD that had 2 GB of RAM in it and all was well. > Today, I installed 4 GB of RAM (2 x 2 GB). The 4 GB shows up in the BIOS > and Windows Vista can see the 4 GB (multibooting) but FreeBSD and > OpenSolaris can only recognize 3 GB. I put the snv_115 install CD in and > booted from it and even GRUB thinks I've only got 3 GB (3143195K). Can > anyone shed some light as to what might be going on?
I suspect the 4GB reported by Windows is the installed amount of ram, not the usable amount of ram. I think in task manager Windows shows the usable amount of memory, and you'll probably see the same 3GB that all the other OSes are reporting. ~1GB is lost because the address space is used for PCI device memory mapped i/o ports, apic registers, pcie memory mapped configuration space, etc... Some chipsets are able to remap the memory that is lost because of the pci memory mapped address range to a physical address >= 4GB. Unlike 32-bit Windows, 32-bit Solaris would be able to use that memory >= 4GB. But it seems that Dell system is using the Intel 915G chipset, and Intel documents that this chipset can't address memory >= 4GB (Section 8, in http://www.intel.com/Assets/PDF/datasheet/305264.pdf): »The GMCH supports 4 GB of addressable memory space...« »Addressing of memory ranges larger than 4 GB is NOT supported.« -- This message posted from opensolaris.org _______________________________________________ opensolaris-discuss mailing list [email protected]
