NV Control Panel: low latency mode Ultra--impressive!

[Noel 4,499]

Not sure what this does, but graphically I'm not seeing any downside.  What's remarkable is I'm seeing roughly a 12% performance improvement (using the surrogate, GPU utilization %).   As a vsync to 30Hz user I'm not looking for frame rate increases of course because I'll never see them, just looking to keep GPU utlization percentage well below 99%.   What I've seen now is I can go from 99% utilization and frames threatening to dip below 30 w/o this mode enabled, and with it enabled to the Ultra setting that will drop down to around 87% or so.  Remarkable and I'm not seeing a downside.   Works for me!

[micstatic 4,319]

Which sim?

[Noel 4,499]

1 hour ago, micstatic said:

Which sim?

I only tried this last eve and I was in MSFS at the time.   If it's disabled for you by default, try flying then pause and change to Ultra.  It should repaint the screen and appears to take effect and if you see what I'm seeing will see the drop then.  If you change it back to off, I don't think it will repaint the screen so I think you will stay at that same GPU utilization.  What I did to confirm was create and save a spot w/ 99% GPU load in a flight w/ low latency mode disabled, shut down to desktop, then make the change to Ultra, restart MSFS and reload that flight, and the same change occurred, about 12%.

[Bert Pieke 7,585]

DX11 only!

Quote:

This works with all GPUs. However, it only works with DirectX 9 and DirectX 11 games. In DirectX 12 and Vulkan games, “the game decides when to queue the frame” and the NVIDIA graphics drivers have no control over this.

Here’s when NVIDIA says you might want to use this setting:

“Low Latency modes have the most impact when your game is GPU bound, and framerates are between 60 and 100 FPS, enabling you to get the responsiveness of high-framerate gaming without having to decrease graphical fidelity. “

In other words, if a game is CPU bound (limited by your CPU resources instead of your GPU) or you have very high or very low FPS, this won’t help too much. If you have input latency in games—mouse lag, for example—that’s often simply a result of low frames per second (FPS) and this setting won’t solve that problem.

Warning: This will potentially reduce your FPS. This mode is off by default, which NVIDIA says leads to “maximum render throughput.” For most people most of the time, that’s a better option. But, for competitive multiplayer gaming, you’ll want all the tiny edges you can get—and that includes lower latency.

[Noel 4,499]

Thanks Bert, I'm GPU bound so this is a big plus in MSFS.  What I notice is:  when the GPU is maxed and now FPS is starting to dip below it vsync'd 30 when the LLM is on Ultra GPU utilization drops down to high 80's% and frame rate is no longer threatened, so it works.  New ball game when DX12 arrives for MSFS.  I haven't flown P3D w/ it yet so don't know how it will fare there.

Cheers

[LRBS 947]

Nvidia “Max Frame Rate” Settings*:

*Introduced in Nvidia driver version 441.87

• If an in-game or config file FPS limiter is not available and framerate exceeds refresh rate:
  Set “Max Frame Rate” to “On,” and adjust slider to (a minimum of) 3 FPS limit below display’s maximum refresh rate.

---

Low Latency Mode* Settings:

*This setting is not currently supported in DX12 or Vulkan.

• If an in-game or config file FPS limiter is not available, RTSS is prohibited from running, a manual framerate limit is not required, and framerate exceeds refresh rate:
  Set “Low Latency Mode” to “Ultra” in the Nvidia Control Panel. When combined with G-SYNC + V-SYNC, this setting will automatically limit the framerate (in supported games) to ~59 FPS @60Hz, ~97 FPS @100Hz, ~116 FPS @120Hz, ~138 FPS @144Hz, ~224 FPS @240Hz, etc.
• If an in-game or config file FPS limiter, and/or RTSS FPS limiter is available, or Nvidia’s “Max Frame Rate” limiter is in use, and framerate does not always reach or exceed refresh rate:
  Set “Low Latency Mode” to “On.” Unlike “Ultra,” this will not automatically limit the framerate, but like “Ultra,” “On” (in supported games that do not already have an internal pre-rendered frames queue of “1”) will reduce the pre-rendered frames queue in GPU-bound situations where the framerate falls below the set (in-game, RTSS, or Nvidia “Max Frame Rate”) FPS limit.

Windows “Power Options” Settings:

Windows-managed core parking can put CPU cores to sleep too often, which may increase frametime variances and spikes. For a quick fix, use the “High performance” power plan, which disables OS-managed core parking and CPU frequency scaling. If a “Balanced” power plan is needed for a system implementing adaptive core frequency and voltage settings, then a free program called ParkControl by Bitsum can be used to disable core parking, while leaving all other power saving and scaling settings intact.

Maximum Pre-rendered Frames*: Depends

*As of Nvidia driver version 436.02, “Maximum pre-rendered frames” is now labeled “Low Latency Mode,” with “On” being equivalent to MPRF at “1.”

A somewhat contentious setting with very elusive consistent documentable effects, Nvidia Control Panel’s “Maximum pre-rendered frames” dictates how many frames the CPU can prepare before they are sent to the GPU. At best, setting it to the lowest available value of “1” can reduce input lag by 1 frame (and only in certain scenarios), at worst, depending on the power and configuration of the system, the CPU may not be able to keep up, and more frametime spikes will occur.

The effects of this setting are entirely dependent on the given system and game, and many games already have an equivalent internal value of “1” at default. As such, any input latency tests I could have attempted would have only applied to my system, and only to the test game, which is why I ultimately decided to forgo them. All that I can recommend is to try a value of “1” per game, and if the performance doesn’t appear to be impacted and frametime spikes do not increase in frequency, then either, one, the game already has an internal value of “1,” or, two, the setting has done its job and input lag has decreased; user experimentation is required.

[Noel 4,499]

It reduced the work demanded of the GPU by about 12% which is nothing to sneeze at for a freebie over the default setting of OFF for LLM.  My CPU is usually snoozing while running MSFS so no worries about the CPU not being able to keep up.  I had assumed vsync to 30Hz was going to be all of the reduction of workload for the GPU I could find but this adds a significant boost over and above that.

[captain420 3,099]

Would this setting benefit my current setup? I am also GPU limited in the sim. and I run at 4K ultra preset. I am running on a 55" Samsung 4K TV @60Hz refresh rate.

What settings should I change in order to see ths 12% increase in performance?

Edited October 4, 2020 by captain420

[Noel 4,499]

5 hours ago, captain420 said:

Would this setting benefit my current setup? I am also GPU limited in the sim. and I run at 4K ultra preset. I am running on a 55" Samsung 4K TV @60Hz refresh rate.

What settings should I change in order to see ths 12% increase in performance?

You can do what was suggested in the title, Low Latency Mode set to Ultra. You may not experience this if you're not running vsync to 30Hz, but it's easy to try for yourself.

[G-RFRY 1,711]

In the Asobo Q&A last week when the head dev was asked about DX12 he said bringing DX12 to MSFS is needed for PBR and DLSS but will not increase performance that some users think it will, DX12 will however put more load on your GPU as we know it was with P3Dv5. 

The Q&A is on YouTube if you want to watch it, on the end it mentions seasons a long long way off to much work needed. 

Edited October 4, 2020 by G-RFRY