Vulkan: VK_PRESENT_MODE_MAILBOX_KHR with two images equivalent to VK_PRESENT_MODE_FIFO_KHR?
<p>I wrote some Vulkan code and I think I am hitting some driver bugs (Linux, mesa 13, intel). The driver only offers <code>VK_PRESENT_MODE_MAILBOX_KHR</code> (spec violation). I was under the impression that if I create my swap chain with an imageCount of 2, the resulting behavior should be equivalent to <code>VK_PRESENT_MODE_FIFO_KHR</code>.
My reasoning is that one image is being presented, so the swap chain will only give me an image and signal its availability (<code>vkAcquireNextImageKHR</code> with semaphore) if the other one was submitted. Then it would swap out which image is being presented on the next vblank completion.
However, I get very high framerates, so it is clear that not all images are actually presented.
Is it possible that the present engine does some kind of blit to internal memory and releases the image practically immediately?</p>