I think I feel very foolish?

Blando Calrissian

I've been using Daz since 2020, have had my current rig since June of 2021, and today was the first day I realized that I could make my computer render much more quietly by turning off the CPU box in the render advanced settings.

If you check the CPU box and the GPU box, how much of the work does the CPU take on during an Nvidia Iray render?

 

Gordig

The amount of work the CPU does is almost beside the point. What really matters is that a GPU, even a fairly low-end one, is much more efficient at rendering than even a high-end CPU. This means that the GPU gets throttled so that the CPU can keep up.

Richard Haseltine

Gordig said:

The amount of work the CPU does is almost beside the point. What really matters is that a GPU, even a fairly low-end one, is much more efficient at rendering than even a high-end CPU. This means that the GPU gets throttled so that the CPU can keep up.

I don't think that is the issue, it seems more likely that it is because the CPU is trying to do two jobs (render, and manage the rendering) so there is a risk it will be fully busy when the GPU wants to return an iteration and so the GPU will have to wait a bit, not doing anything useful.

crosswind

...and even if you have a very strong CPU, a "concurrent rendering" with both GPU and CPU may only save your 5 ~ 10% rendering time, let alone in this way, CPU's frequency is downgraded as well as not fully loaded.

So always rendering with GPU(s) is an optimal way as long as you do not run out of VRAM...

Roman_K2

I had a notion that AMD was not so good for use with DS... this is the first time I've seen a mention of an AMD cpu mated up with an Nvidia graphics circuit.

Richard Haseltine

Roman_K2 said:

I had a notion that AMD was not so good for use with DS... this is the first time I've seen a mention of an AMD cpu mated up with an Nvidia graphics circuit.

I think quite a few of us have AMD CPUs with nVidia GPUs.

crosswind

I have to say my AMD CPU has been working very well with nVidia GPUs as well as DS for sure.

Roman_K2

Soooo... I am in the market for a lower end, low height (although my machine is a regular size desktop) maybe, Nvidia card. Machine is a Dell 7020, bought used. To me it seems pretty speedy - 500 Mb SSD for the boot device, 16 Gb RAM and 1 TB storage plus a 2 TB external is connected most of the time.

Any comments? I think I see... older Nvidia cards for sale on Amazon and I think Ebay.

Roman_K2

Of course the corollary to this ^ ^ ^ is to just be normal and get a purpose-built machine or laptop with Nvidia 3020 or 3030, maybe 3040 internals. About $1,200.00 hereabouts, seems like.

Richard Haseltine

Roman_K2 said:

Of course the corollary to this ^ ^ ^ is to just be normal and get a purpose-built machine or laptop with Nvidia 3020 or 3030, maybe 3040 internals. About $1,200.00 hereabouts, seems like.

How much memory do those have? There is no point in buying anything with less than 8GB for Iray, and even that is pushing it for many purposes.

Roman_K2

Um, 8 Gb minimum these days, with some 16's and 32 Gb is not... unheard of. OTTOMH I don't remember how much VRAM.

It occurred to me that maybe my issue - if indeed I have one - was with the *Radeon graphics* cards and not the CPU. Weren't the Radeon cards kind of frowned on by DAZ Studio users, some years back?

Gordig

Roman_K2 said:

Um, 8 Gb minimum these days, with some 16's and 32 Gb is not... unheard of. OTTOMH I don't remember how much VRAM.

It occurred to me that maybe my issue - if indeed I have one - was with the *Radeon graphics* cards and not the CPU. Weren't the Radeon cards kind of frowned on by DAZ Studio users, some years back?

They're not "frowned upon" so much as they just don't really do anything inside DS. 3Delight is CPU only, and Iray can only be accelerated by NVidia GPUs.

Roman_K2

Richard Haseltine said:

There is no point in buying anything with less than 8GB for Iray, and even that is pushing it for many purposes.

Thanks. I actually did not know this - probably because I have too much tech swirling around in my head.

Vaguely related: in recent months I have actually seen the bigger Nvidia cards - or at least the empty boxes - on display at local "Staplers" outlets. I guess they cost a few hundred dollars and up. You take the box to the cash and staff fetch the item from the back room.