Does anyone know exactly what the "Slow HDD Mode" option does? It just says to run it if you're running a slow hard drive. I'm running the game on a 2TB mechanical drive, 7200rpm but it's pretty full. I don't seem to notice any major difference in load times, data streaming, or overall game performance when I run it so I'm just curious if anyone knows what it actually does and if there is a difference that I'm just not noticing.

My guess is that "slow HDD mode" was meant for 5400 RPM discs, which are what PS4/Xbox One use by default.

I don't see any difference when I activate it either, then again, I have a SSD. You will only really notice an improvement in assets loading times with a slow HDD such as a 5400 RPM in SATA II interface, that's my guess.

Supposedly it loads more world data into ram, Maybe it's a Placebo also.

Hmm okay, then I probably wouldn't notice it given the fact that I have a 7200rpm drive. Thanks for the responses!