Daz Still frustrated with Iray render speed? Try this.

[function2020]

Until few months ago, I hated Iray so much because it cost sooo long time for render. I tried Filament and Octane, all have problems on dealing with Iray materials, lights, etc.
After in detail analysed those render parameters, now Iray works very well on my 1080ti pc (I canceled plan to upgrade 3080), no picture would cost more than few minutes render time, and can achieve good quality (not excellent).
Here is my settings, strongly recommend DAZ Iray users to try it:

 

[Fatalmasterpiece]

Yes, you're on the right track, turning off render quality is key. Render times depend as much on what is going on in the scene as your settings. Number and power of lights, number of figures, resolution etc.

Max samples can be increased as needed... I like to do around 900 typically with denoiser set to 880. Some people prefer MCJ.

Max path length effects the number of bounces light makes. Makes a difference in scenes with lots of reflections. Setting this to -1 means they continue until their luminance drops to nothing so setting it to 7-10 helps performance but isn't as accurate as -1.

Nominal Luminance works like ISO on a camera. You're telling Daz how much light there is in a scene and adjusts the firefly filtering. If set to 0 it is automatic based on tonemapping. Personally have never needed to set it to anything other than 0. My tonemapping is almost always set to 13-14.

This site offers some great info on the subject.

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[MissFortune]

I wouldn't cancel your plans for a 3080, seeing as the 40 series might not be far off. You'll likely be seeing a rush of 30 series cards hit the market for those rich kids/miners who don't need them after getting the latest and greatest. At the end of the day, you have to understand that a 30 series card is three generations newer than a 1080ti. A 3080, for many programs, will be leagues better (speaking from experience here as I've jumped from a 1660 Super to a 2070 Super to a 3080. All of which have had clear performance improvement over each other). This is stuff aimed at weaker/lower-end hardware, but it's not labeled as such - nor are the trade-offs for speed gained.

The Daz denoiser is probably the worst of what's out there. You're better off using the Intel and/or Nvidia AI denoisers (or both with the DnD fork) and just outright ignoring it in Daz. You'd probably be better off setting your samples to around 500 and using a denoiser afterwards. For contrast, I usually set my samples to 7800 or so on 1440p renders (most are usually done at 2500-5000, depending on the complexity of the render) with max time at zero, the finish times usually vary anywhere from twenty minutes. The more characters/props in the scene, the longer it'll take. Same goes for the weight (and/or textures used within it. Stonemason, for example, has some great environments/scenes but you'll need a fairly beefy system to work with them consistently) of the scene itself. Then there's lighting, reflections, and so forth.

At the end of the day, it's basically choosing quality vs quantity/time vs efficiency. I prefer the quality, but then I'm also able to render faster than most. What someone else chooses to do is certainly up to them.

 

[ThanatosX]

Also important, the newer cards have a larger amount of memory along with the generational improvements.

 

[Rich]

Until few months ago, I hated Iray so much because it cost sooo long time for render. I tried Filament and Octane, all have problems on dealing with Iray materials, lights, etc.
After in detail analysed those render parameters, now Iray works very well on my 1080ti pc (I canceled plan to upgrade 3080), no picture would cost more than few minutes render time, and can achieve good quality (not excellent).
Here is my settings, strongly recommend DAZ Iray users to try it:

I've seen recommendations by some people (for some scenes) to go even lower than what you're showing - 5-6. Dialing down the number of light bounces iRay will try definitely does help render time. Where you can get in trouble with this (and you can always set it back) is if your scene has a close-up of a character, because the eyes are a fairly complex structure combining transparency and translucency. Without the extra bounces, things can look odd. But, of course, for those scenes you can always dial it back up. Similarly, dialing things down too far when you have mirrors or other reflective items in the scene may give you some artifacts.

But, in general, this is good advice for people struggling with render time.

 

[Deleted member 1121028]

With best quality and skins in mind:

I would stay from denoisers (Nvidia/Intel), as they have no buffers to work correctly, it's very raw. In part because how Uber/PBRSKin and Daz/Iray work. Internal denoiser (Optix) can be great while working in Iray preview to build your lightening. I think the most common problem with denoisers is to keep Daz skin integrity and details.

I stay generally at -1 path lenght out of lazyness, problem with reducing bounce is how it affects reflection (especially when using HDRI as main light source) and specularity/roughness (also caustics but hey). Which are quite central on how (good) Daz skin are made. That said I'm sure there is some sweet spot to find over distance while keeping quality tho.

Lowering pixel radius can be tough, it's betting for texture sharpness over aliasing. I'm torn on this one. First because you could sharp your textures before rendering. For some close up it ain't gonna work great (more likely to happen under ~1.2), especially for well made hair or sometime even a simple jaw or noise line/piece of cloth/jewellery/glasses and so on.

Use and know how to use Iray plane(s). I can't stress this enough. It is central (imho) to keep rendering time all time low and indecent quality. It's your main weapon against rendering time.

Note, this is for milking best quality you can on decent card o/
There is also few tricks with tone-mapping but it's not really academic lol.