ZDoom

Judging by comments in other threads, I don't think this is unique to me/my system, but I also don't think it's a bug as such.

In recent versions of GZDoom, I have noticed that momentary stuttering/pausing happens as the game is doing *something* in the background. It is my impression that it tends to happen when things are being seen for the first time.

I know that the obvious assumption is that resources are loading (and that could well be the case). However, from discussions I've had on the VkDoom Discord, the stutters/pauses feel very much like the ones that can happen with VkDoom when a shader is being compiled as you come across something using it for the first time. The difference being that, with VkDoom, the stutters/pauses are far more severe (for me anyway). I also understand that GZDoom and VkDoom have different principles behind how they cache their shaders. So, I might be barking up the wrong tree entirely.

The thing is, it's quite a new phenomenon. If I go back a few GZDoom versions, I don't experience the problem. I happen to have g4.8pre-69-g5ca3ab3fc installed and I don't get the same issues with it. So, something has changed.

Like I said, I don't think it's a bug. I'm just putting this out here in case there is someone has any insight or a way of reducing the problem. It's not that severe in GZDoom, but it does sometimes cause quite a "lumpy" performance during the game and it can detract from the experience.

I have also been seeing this problem lately, on different PCs.

Another thing I am seeing is a general 'stutterness' when using VRR at very high fps that isn't due to any framerate/frametime issues. The animation simply isn't as fluid as it should be at something like 300-400 fps and Hz. I can definitely say that GZDoom's (and VkDoom's) reported framerate often differs significantly from the monitor's reported refresh rate, as if the monitor wasn't able to keep up with the game for some reason.

I've noticed the latest Nvidia drivers have some problems, using the December 2024 ones, I am using this profile without stuttering on a RTX 4070 and GZD 4.14
https://i.postimg.cc/dt0fn5fh/immagine.png

on previous drivers versions I've noticed the stuttering disappeared setting the DXGI Swapchain on the presentation setting, now seems the setting does nothing

oh and VSync disabled in GZDoom with a FPS cap at 144 FPS (the same as my monitor's refresh rate)

It could well be a driver-related thing, but there is an element of it that is GZDoom related too. I say that because I do not get the same level of stutters/pauses on loading new resources (or whatever is causing it) with an older version of GZDoom (specifically g4.8pre-69-g5ca3ab3fc which i just happen to still have on my HD), loading the exact same files and using an identical ini.

Whether that's because GZDoom is doing something differently itself, or whether it's because it's asking the driver to do something that it didn't previously (and, if so, the driver is presumably being inefficient) I can't tell.

It's not massively problematic, but it is "lumpy" enough to detract from gameplay a bit.