Hi @r.torres
Thanks for your comment. We will make sure that in the next version this is going to be flawless and we will automatically use all the available GPU-s.
At the moment you need to set some environment variables for Redshift on each computer. If you are using V-Ray then you can use an utility to do it, please follow this guide: V-Ray GPU Setup - V-Ray for 3ds Max - Global Site
Alternatively, you can use the supplied GUI tool, which you can find in Start Menu > Programs > V-Ray 6 for 3ds Max #### > Select rendering devices for V-Ray GPU for 3ds Max #### , where #### is the 3ds Max version.
After changing this option, you need to restart the 3ds Max (or V-Ray Standalone) if it is running for the changes to take effect. If the V-Ray GPU render server is running as a Windows service, you may need to stop it from the Services applet in the Control Panel.
Hope this helps!