Question concerning internal queue organisation

Hello, my first post here :-) About half a year ago i started with C++ (did a little C before) and poking into graphics programming. Right now i am digging through the various vulkan tutorials. A probably naive question that arose is: If i have a device (in my case a GTX970 clone) that exposes on each of two gpus two families, one with 16 queues for graphics, compute, etc and another one with a single transfer queue, do i loose potential performance if i only use 1 of the 16 graphics queues ? Or, in other words, are these queues represented by hardware or logical entities ? And how is that handled across different vendors ? Do intel and amd handle this similar or would a program have to take care of different handling across different hardware ? Cheers gb