Roughly speaking - you can't. This is a property of the architecture. If you have more than 4GB, something around 700 Mb indeed is lost for the user. This does not depend in the motherboard.
> Hi there, > I have a dual-opteron with 8GB of ramm installed (8x1GB dimms) on a > Tyan K8W (S2885). > But linux only uses 7.3 Gb... > Linux on boot detects correctly the available 8Gb: > > [EMAIL PROTECTED] ~> dmesg|grep -i mem > Node 0 MemBase 0000000000000000 Limit 00000000ffffffff > Node 1 MemBase 0000000100000000 Limit 00000001ffffffff > Bootmem setup node 0 0000000000000000-00000000ffffffff > Bootmem setup node 1 0000000100000000-00000001ffffffff > HighMem zone: 0 pages, LIFO batch:1 > HighMem zone: 0 pages, LIFO batch:1 > Memory: 7391892k/8388608k available (2655k kernel code, 0k reserved, > 700k data, 200k init) > agpgart: Maximum main memory to use for agp memory: 7956M > Freeing unused kernel memory: 200k freed > ohci_hcd 0000:03:00.0: irq 19, pci mem 0xfc8fd000 > ohci_hcd 0000:03:00.1: irq 19, pci mem 0xfc8fe000 > > Note: > Memory: 7391892k/8388608k available (2655k kernel code, 0k reserved, > 700k data, 200k init) > > Now, I've seen that this unused memory is related to pci && AGP dma maps.. > But, on my sparc I also have PCI and I don't have these problems > (4gb real, 4gb used..) > And on dual-opterons with 8GB from HP (rack 1u, don't recall model name) > I also have 4Gb real, and 4Gb being used. 4GB or 8GB ? Memory hole appears if you exceed 4GB > > So, does anyone know how to make this system really use the 8GB of ram.. > > Having 700MB of fast ram being unusable isn't very to my taste... > > -- > Miguel Sousa Filipe > > -- > [email protected] mailing list -- Dmitri Pogosyan Department of Physics Associate Professor University of Alberta tel 1-780-492-2150 412 Avadh Bhatia Physics Labs fax 1-780-492-0714 Edmonton, AB, T6G 2J1, CANADA -- [email protected] mailing list
