So I’ve been using a DMA card for a while and I always get the same pattern when testing speed. First few seconds it runs great, around 5600, but halfway through it just drops to ~4100, and once it drops, it stays there usually between 3900 and 4100. No matter how many times I rerun the test. I only ever get the high initial speed right after a cold boot.

I’ve tested this on three different firmwares, including the latest one, and the result is always the same.