Max FPS Matching Refresh Rate?

[jasontschantre]

I am using a PC with a GTX 980Ti video card, and I'm sending a 3840x2160 signal via HDMI into a Datapath FX4. It appears that with HDMI, and this datapath, at 4K, the maximum refresh rate I can have is 30Hz.

Now, when I output my 4K Resolume composition to this external display, the fps drops from a solid 60fps, to a solid 30fps. Is this because Resolume automatically detects the refresh rate of the external display, and adjusts accordingly?

In other words, is this intentional, and is the software and hardware working as it should, or should I be concerned about the drop in framerate?

I am fine with a solid 30fps, especially if that is the refresh rate on the external display anyway. Just want to understand further, and hoping it's not that this card with Resolume just can't handle the workload.

[lightbx]

Hey Jason, sounds like fun mapping uncharted waters with the new FX4

As far as I know, the X4 also requires 30hz at 3840x2160 (the below thread explains the signal flow in detail):
viewtopic.php?f=12&t=13361&p=54904#p54904

If DL-DVI and HDMI or DP have similar clock specs, the rule may still apply with the FX4, but I can't say for sure if that means Resolume necessarily has to run at 30fps. Oaktown, the forum's resident Datapath wizard, may be able to answer that.

One possible solution may be to disable vertical sync in the GeForce driver. I know this can double your framerate, but can also lead to visible tearing on your displays. However, if the Datapath locks down the refresh rate, this may not be an issue, and you should see your base framerate jump to 60fps. You could also just disable vertical sync for Arena specifically. Cheers!

[jasontschantre]

Thanks this is all really good info, and glad to see resolume has been tested so much with datapath. Need to study this more to fully get all this info. What I'm wondering though is the reason resolume's reported fps drops. It happens the second I point a screen to the external display (which again is the fx4 via HDMI @3840x2160@30hz) rather than a virtual display.

[Oaktown]

@Lightbx, the Datapath Fx4 offers the choice of three inputs, two HDMI 1.4, supporting 4K at 30fps and one DisplayPort 1.2 input capable of 4K at 60fps. The 4 outputs are still 1080p60.

[Joris]

What I'm wondering though is the reason resolume's reported fps drops.

Resolume caps to the refresh rate of your output. No point in rendering 30 extra frames every second when they get thrown away anyway.

[jasontschantre]

Cool, glad to know that. And yeah it makes sense.

I was able to pick up a displayport cable today, so now I'm sending a 60hz 4k signal to the datapath, and lo and behold Resolume is now reporting between 59.94 and 60.04 fps.