I would have expected that doing an asynchronous Read() call in your main thread versus doing a synchronous Read() call in a background thread would have about the same effect, namely, not stalling the main thread.

Any recent (< 10 years old) HDD controller uses DMA, so it can push data read directly into RAM on its own without anything but marginal CPU control. An asynchronous Read() call can thus be more resource-friendly.


Some things to check:

Just to make sure, when your thread isn't doing anything, you're waiting using WaitForMultipleObjects() (or the equivalent pthreads call), not burning the CPU with a while(queue.empty()) {}, right? Otherwise, maybe it might not be the loading that leads to glitches, but the times inbetween ;)

Another place to check would be resource generation. It might take some time to create graphics device resources, so you might want to use a time budget for creating the resources if you aren't already doing so.

Maybe it would even be sensible to use a two-layered approach, run a high-priority thread for loading files (this thread idles most of the times, waiting for new files to enter the queue or files being loaded to finish loading) and a low-priority thread that creates the graphics device resources.