Will quality of render be the same when using different GPU's?

dawgzang

Hi

I am looking at buying a new computer because my old one is really old. There are so many different GPU options in pre-built systems my question is this.

If I render an iray image until it finishes will the quality be the same on a GTX 1650 or a RTX 3080 card? I understand the time will take longer on the 1650 but if you let them finish or even set the scan at 1000, will the image quality look identical.

alexhcowley

Which graphics card you buy will have no effect on the quality of the render.  As you've already figured out, the render will complete much faster on the 3080. It also has significantly more memory so it will be able to handle larger, more complex scenes.

Cheers,

Alex.

PerttiA

In theory the quality would be the same, but... The GTX 1650 has only 4GB's of VRAM which limits severely the size of the "scene" - One G8 figure with lightweight textures, clothing and hair, nothing else on the scene already requires about 3GB's of VRAM.

dawgzang

PerttiA said:

In theory the quality would be the same, but... The GTX 1650 has only 4GB's of VRAM which limits severely the size of the "scene" - One G8 figure with lightweight textures, clothing and hair, nothing else on the scene already requires about 3GB's of VRAM.

So are you saying daz would crash or not work if the scene needed more than 4GB's or would it just take longer because some how the magical elves are swaping data in some virtual storge space as needed?

Leana

DS would not crash if the scene uses more than 4GB, but it won't be able to use your GPU at all to render, only the CPU.

jestmart

It will drop to CPU if you have set in the advance render settings.  CPUs are not as fast as GPUs when it comes to number crunching.

dawgzang

Leana said:

DS would not crash if the scene uses more than 4GB, but it won't be able to use your GPU at all to render, only the CPU.

Good to know. If the scene is say Iray 5GB would it only use the CPU and no GPU, or some combination of both if they were both selected?

PerttiA

dawgzang said:

PerttiA said:

In theory the quality would be the same, but... The GTX 1650 has only 4GB's of VRAM which limits severely the size of the "scene" - One G8 figure with lightweight textures, clothing and hair, nothing else on the scene already requires about 3GB's of VRAM.

So are you saying daz would crash or not work if the scene needed more than 4GB's or would it just take longer because some how the magical elves are swaping data in some virtual storge space as needed?

No, if the scene doesn't fit in available VRAM (OS+DS+Scene base load is maybe 600MB to 1GB), the GPU throws in the towel and the rendering is done by the CPU at snails pace (hours instead of 5-15 minutes)

There is no swapping to any virtual space available.

Leana

dawgzang said:

Leana said:

DS would not crash if the scene uses more than 4GB, but it won't be able to use your GPU at all to render, only the CPU.

Good to know. If the scene is say Iray 5GB would it only use the CPU and no GPU, or some combination of both if they were both selected?

Only the CPU. It can only use the GPU if the whole scene fits in the GPU VRAM.

PerttiA

dawgzang said:

Leana said:

DS would not crash if the scene uses more than 4GB, but it won't be able to use your GPU at all to render, only the CPU.

Good to know. If the scene is say Iray 5GB would it only use the CPU and no GPU, or some combination of both if they were both selected?

The GPU would not take any part in IRAY rendering if the scene doesn't fit in available VRAM. 

dawgzang

So go for the most vram if I can afford and then most CPU cores. Thanks everyone!