It looks like you're using an ad blocker! I really need the income to keep this site running.
If you enjoy BlenderNation and you think it’s a valuable resource to the Blender community, please take a moment to read how you can support BlenderNation.

Quick tip - Cycles Viewport Preview Fix

If you have a fast GPU, then this tip by Austere Grim will be a huge improvement of the Cycles preview quality!


  • Joseph FORET

    Nice tip ! Preview is smoother now.
    My GPU seems to work 20 or 30% more with this improvement (Simple scene with GTX 570).

  • Kirill Poltavets

    Good tip! Thanks!
    People, don't forget to set min. tiles back to lower values when you're rendering complex scenes (by GPU) or you'll get an error (on Windows surely... other OS - don't know).

  • Shank

    I have a really fast GPU..
    unfortunately, it's called AMD, and it doesn't support CUDA..
    it would be really nice if AMD user can get a working openCl support, even if it's still unstable, so at least we can hope that one day we can use our GPU on cycle.

    • C

      You can do some hacks to get it working a little bit -- ... the main problem is mainly at AMD's side... not blender's side... amd cards tend to hate on large size kernels

      • Shank

        I've tried it, it just compiling render kernel forever when using 2.63. i've tried 4 different build. I've waited for almost 5 hour. i've installed APP SDK 2.7. My GPU is HD 6850 + HD 6970, i've tried using only 1 GPU. Still nothing. It only work in Blender 2.62, but it's just clay render.
        This is just so sad..

      • Alan Lancaster

        I guess this could be a result of having started Cycles on CUDA, nVidia cards (bar 6xx) have generally had less, more powerful cores (580 has 512 i *think*) than AMD (7970 has 2048) and perhaps handle larger kernels better?

        It has been shown that OpenCL AMD can run GPU only path tracers (SmallLuxGPU2, Indigo and vRay RT [vRay RT seems to have issues]) so partly the architecture of Cycles is also ill suited to AMD card architecture.

        Of cource despite OpenCL being vendor indepenent, different cards have different internal architectures and work quite differntly :P

  • Indy

    This tip could be really quick, max 2 min. Just think what to say and/or write it

    • Reaction

      +1. Great tip, but garbled presentation.

      • Totsch

        Check his web site. It is called - no joke: Horrible Blender Tutorials... ;)

        • Totsch

          oh... btw: thanks for this cool tip Austere Grim!

  • dbeaton

    If changing the value from 64 to 1024 slows the preview down too much, values of 128, 256, etc. will also reduce the size of the pixilation to some extent. Also, reducing (or eliminating) the amount of children in the preview box for hair particle systems helps a lot, as well as simply reducing the size of the viewport.

    • chicortiz

      Hey great tip, specially the viewport size one. Thank you dbeaton! Another one: make sure all visible objects are inside the 3D viewport while orbiting everyone! It took me ages to figure that out XD ;)

  • almon

    Good progress. Still a little far for a high image quality realtime viewport (something like modo viewport:, but in the good way :D
    Keep the good work.

    • chromemonkey

      Okay, who downvoted almon's comment and for what reason?


    Fast GPU is the key I am rendering a scene and checking out your tips . Thanks much .

  • onjoFilms

    Unfortunately, Expiremental render settings don't work on the latest iMac. Says OpenCL build failed. :(

  • chicortiz

    Is this Blender 2.63.11 r47769? Thank you!

  • Ross M

    I imagine this would be no good if your model was more complex than just a monkey and a few planes...

  • MD

    It would be great if there would be an option that achieves this:
    Whenever I rotate/translate/scale and object or shift/zoom/orbit my view the viewport automatically switches to solid or wireframe mode and then as soon as I let go it switches back to rendered view. This way we have both the benefits of changing stuff with instant feedback and also seeing a quick preview render as soon as we let go.

Share this story: