alt Hacker Newscan someone explain me like I'm 10 what is a BAR?
Like it says something about mmaping 256 GB of per GPU. But wouldn't it waste 2T of RAM? or do I fail in my understanding of what "mmap" is as well..
EDIT: yes, seems like my understanding of mmap wasn't good, it wastes not RAM but address space
Base Address Register
this term can be used at a couple different points (including mappings from physical addresses to physical hardware in the memory network), but a PCI BAR is a register in the configuration space that tells the card what PCI host addresses map to internal memory regions in the card. one BAR per region.
the PCI BARs are usually configured by the driver after allocating some address space from the kernel.
DRAM BARs in the switching network are generally configured by something running at the BIOS level based on probes of memory controllers and I2C reads from the DIMMS to find out capacity.