John Martin wrote: > jean-francois simon wrote: >> hi >> i am using a nvidia quadro - fx5500 on opensolaris running on a >> core2duo platform. >> nvidia says it has 1GB of video ram and i was surprised not to see it >> all mapped in pci BARs: >> >> ... >> >> from the above xorg.0.log i can see it has only 256MBytes mapped through >> pci bars. is this normal? >> > Yes. The size of the framebuffer aperture is purposely restricted as to > not overwhelm the limited amount of physical address space (low 4GB) needed > by all the devices on the system. Imagine the problems caused by putting > four of these boards in a system if the aperture was 1GB. > > The driver knows how to get at all the memory, so none of it is being > wasted. > >
do you know if this feature of hiding video ram is common in the video adapter world? i was under the impression that (at least on 64b platforms) a large MMIO window such as one caused by a 1gb graphic card, will not a problem as the chipset remaps overlapping main memory above 4gb. thx -jfs
