GPU latency is the amount of time your CPU wastes doing nothing while it waits for the GPU to catch up. A high latency means you are giving the GPU a lot more work than the CPU (relative to what they can handle). What this also means is you can add more CPU intensive tasks (physics, AI, etc.) without affecting framerate since the CPU is already waiting on the GPU. If you are having framerate issues with high GPU latency, then you’ll need to tone down your graphics effects. It is hard to tell which effects are slowing down your scene without knowing more about your scene. If your framerate is fine, then I wouldn’t worry.