Fan Start Behavior: RPM overshoot on RTX 5000 series GPU [V251]

[thanksgivingdude]

Question: GPU fan spin-up overshoot from 0 RPM (RTX 5000 series)

When my RTX 5090 GPU fans are started from an off state (0 RPM) via FanControl, either through manual control or a graph, it briefly ramps well above the target RPM before settling around 1100 rpm @ the minimum 30% enforced by the card.

In the context of tuning a system for minimal noise, the brief ~1400-1500 RPM spin-up is noticeably louder than the VBIOS-controlled fan startup.

Does anyone else observe this behavior on RTX 5000-series GPUs, or know whether this is hardware-specific versus something influenced by FanControl?

Comparison with GPU VBIOS

• When started from 0 RPM via VBIOS (@ 52C): GPU fan ramps to ~1100 RPM at 30% w/ minimal overshoot (if any).
• When started from 0 RPM via FanControl, GPU fan ramps to ~1400–1500+ RPM before settling down to ~1100 RPM at 30%.

[Rem0o]

What's the configured start% in the control card?

[thanksgivingdude]

@Rem0o thanks so much for the reply. I've done testing at various start percentages. I first observed the behavior at a start percentage of 30% while just toggling the fan on and off in manual mode.

I tested with a variety of start percent values ranging from 0% to 40% in manual mode. The results are all similar with the only difference being that the upper test (40%) spikes proportionally higher to 1900 rpm before settling at ~1350 rpm. Tests at 30% and below consistently reproduce the figures cited in my first post (i.e. a spike to ~1450rpm then settles to ~1100rpm). I also reduced the step-up value, but noted no difference.

Below is a visual of the behavior I'm seeing.

Let me know if you need any additional information and I'll happily provide (or if I'm missing something silly here)! Thanks for what you do.

Fan RPM over time for a GPU fan

• The left test is allowing the VBIOS to handle the fan behavior.
• The right two tests are with manual-mode FanControl, note the overshoot.

[Rem0o]

Now that I think of it, when I had my GTX 1060, I had the same behaviour. I don't think that's something that can be controlled from Fancontrol's pov. FanControl just does "go to X %" and the card does the overshoot then. Seems to be a quirck of Nvidia cards when using the manual control.

[thanksgivingdude]

Got it. A work-around is defining a graph at 0% until above the card’s default fan start temp (52C for me). The VBIOS handles spin up, then control transitions to the user graph.