Photoreal devices vs Interactive devices

Sertorial

In the advanced tab of iRay render settings, there are four check boxes

Photoreal CPU

Photoreal NVIDIA

Interactive CPU

Interactive NVIDIA

 

Which ones should I have checked?

Tobor

Iray has two primary rendering modes: Photoreal and Interactive. The Photoreal mode provides the closest simulation to real life, and is the default mode. The separate options allow you the flexibility to choose which rendering device(s) to choose for each mode. Most people don't even use Interactive, but even if so, it's not uncommon to use the same settings for both.

The choice of whether to check CPU and/or a CUDA-based graphics card comes down to numerous individual judgments, so there's no single right answer. The function of CPU-assisted and CUDA-assisted renders has covered extensively in other threads, and even if you read and follow them all, you'll still need to conduct your own tests to see which settings work best for you. So I'd skip trying to make sense of what others have done, and just try it for yourself.

 

Sertorial

Tobor said:

Iray has two primary rendering modes: Photoreal and Interactive. The Photoreal mode provides the closest simulation to real life, and is the default mode. The separate options allow you the flexibility to choose which rendering device(s) to choose for each mode. Most people don't even use Interactive, but even if so, it's not uncommon to use the same settings for both.

The choice of whether to check CPU and/or a CUDA-based graphics card comes down to numerous individual judgments, so there's no single right answer. The function of CPU-assisted and CUDA-assisted renders has covered extensively in other threads, and even if you read and follow them all, you'll still need to conduct your own tests to see which settings work best for you. So I'd skip trying to make sense of what others have done, and just try it for yourself.

Thanks. I have been experimenting a little and found that if I check only my NVIDIA card the render won't start. It needs both to be checked, (or the CPU only to be checked) in order to render anything. Is that normal?

 

Tobor

If you're not getting a render with just your nVidia card selected, it means your card isn't up to the task, and isn't being used. Only CPU rendering is taking place.

The reasons for a nVidia card not rendering Iray include: Not enough video RAM (you generally need 2GB+, and that's for a small scene), outdated video card driver, and hardware too old to support Iray rendering. You can see what's up by trying a render with only the graphics card selected, then choosing Help->Troubleshooting->View Log File. Scroll to the bottom for the latest error and warning messaged.

Sertorial

Tobor said:

If you're not getting a render with just your nVidia card selected, it means your card isn't up to the task, and isn't being used. Only CPU rendering is taking place.

The reasons for a nVidia card not rendering Iray include: Not enough video RAM (you generally need 2GB+, and that's for a small scene), outdated video card driver, and hardware too old to support Iray rendering. You can see what's up by trying a render with only the graphics card selected, then choosing Help->Troubleshooting->View Log File. Scroll to the bottom for the latest error and warning messaged.

Thanks. My card is a GeForce GTX 770 with 2GB of RAM. Is that underpowered for iRay then?

mjc1016

2 GB will basically get you a clothed model in a portrait shot...

Sertorial

mjc1016 said:

2 GB will basically get you a clothed model in a portrait shot...

So not that good then?

Can I add a second GPU to this? (i.e. can two GPUs work together?) If so, what would you recommend? What would be a good NVIDIA card to add?

JimmyC_2009

Sertorial said:

mjc1016 said:

2 GB will basically get you a clothed model in a portrait shot...

So not that good then?

Can I add a second GPU to this? (i.e. can two GPUs work together?) If so, what would you recommend? What would be a good NVIDIA card to add?

You can add a second GPU, however, the Scene has to fit on each card in order to render, in other words haviong two 4GB cards still only gets you 4GB available, and not 8GB.

 

Sertorial

JimmyC_2009 said:

Sertorial said:

mjc1016 said:

2 GB will basically get you a clothed model in a portrait shot...

So not that good then?

Can I add a second GPU to this? (i.e. can two GPUs work together?) If so, what would you recommend? What would be a good NVIDIA card to add?

You can add a second GPU, however, the Scene has to fit on each card in order to render, in other words haviong two 4GB cards still only gets you 4GB available, and not 8GB.

 

Ok. Maybe I should just buy a new card and replace the one I have. I hear the Titan X is pretty nice. I have a 600W power supply, which I presume would be ok?