Yeah, I was looking at GPU Tweak; when I hooked two fans to both headers, there's only one control speed for the EXT fans, which is only in percentage, but the monitor tool can tell the difference in speed per fan. So I think the Fans may be DC control instead of PWM, but knowing that GPUT knows the RPM, I don't know. FYI my motherboard reports the same RPM fan speed as the Strix for one of my fans, so it knows its speed somehow.