Arnold renders in evaluation mode with a watermark if you don't have a license. For production rendering, you need a license.

Arnold licenses allow you to render without a watermark.

All licenses are floating licenses

Sales of node-locked licenses were retired in December 2016. All licenses are now floating licenses, and require a license server.

Arnold licenses use RLM encryption from Reprise Software.

Floating licenses allow any computer on the network to render with Arnold. The maximum number of computers that can render at the same time (concurrently) is determined by the license count. For example, if you have five Arnold licenses, then at most five computers can be rendering at the same time.

Floating licenses require an RLM license server, which manages your use of Arnold through a license key. The license key typically defines the version of Arnold you can use, the number of computers you can use for rendering, and for how long.

Virtual machines and 32-bit machines are not supported as license servers.


Licenses are per-machine

Arnold licenses are per-machine, and there is no restriction on the number of cores or threads used to render. With one license, you can render on as many threads as you want.

You can run multiple Arnold render jobs on a single machine, and they will all share the same license.

Free Arnold plugins

Arnold plugins (such as MtoA, HtoA, SItoA, and C4DtoA) do not require a license. You can install and use any of the Arnold plugins. An Arnold license is required only when you want to render without watermarks.

Licenses are global

Arnold license usage is not restricted to a territory or region.

Floating licenses can be used by computers at multiple geographic locations (as long as they can connect to the license server), and node-locked licenses can be used anywhere (for example, a node-locked license on a laptop can travel with the laptop).

Render farm licensing

Every node on a render farm needs an Arnold license.


For floating licenses, Arnold uses version 11.2BL2 of the RLM license server. 

  • You can download the Arnold license server here.
  • These downloads include both the generic RLM license server and the specific Solid Angle license daemon.
  • The latest version of the RLM license server works with all older versions of Arnold.

You can find more information and troubleshooting help for RLM on the RLM support site.

  • Search the FAQ for common problems with RLM license servers.
  • Review the list of fixed issues, to see if a problem is fixed in a newer release.
  • Read some troubleshooting tips (PDF)
  • Get the License Administration Guide (PDF), which is a technical reference to setting up an RLM license server (this is the same manual that can view from the RLM web admin page)


Further information on how to get the mac address, install and use RLM can be found in the Support :: Licensing section.

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