I notice that the OpenCL Programming Guide changelog indicates that the table of memory behaviour has been updated to include whether or not "VM" is enabled. I don't know what term this refers to, and it is not defined within the guide itself. Virtual machine? Virtual memory? Something else?
I also confused about the VM, i think it should be Virtual Memory. But don't know how to disable and enable it.
I try all mem flags and can not achieve the peak bandwidth of data transfer, only about 3~6 GB/s.