I am also experiencing vkQueuePresentKHR blocking in FIFO mode. Even with mailbox it seems to take a significant amount of time (almost 1ms). It’s a bit unexpected. If it’s worth anything, I used a gsync compatible laptop with a GTX980M.
I don’t see an immediate presentmode either. And I had the same impression, Ziflin, but I guess it depends on the hardware. The spec only says that minImageCount+1 can be expected not to block when calling vkAqcuireImageKHR.
How did the AMD card behave?