# RT using CPU not GPU **URL:** \ **Category:** Issues\ **Created:** [February 21, 2012, 5:16am UTC](https://forums.chaos.com/t/rt-using-cpu-not-gpu/40447 "2012-02-21T05:16:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Peter\_Grealy](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@Peter\_Grealy](https://forums.chaos.com/u/Peter_Grealy)\ **Post date:** [February 21, 2012, 5:16am UTC](https://forums.chaos.com/t/rt-using-cpu-not-gpu/40447/1 "2012-02-21T05:16:43Z")
Hi All, Since the official build V2.2 for Maya came out I noticed that when RT “GPU” engine is selected it still uses the CPUs to render. Like the switch makes no difference, it all renders using all 24 CPUs. Can anyone else report the same issue? Another note, I’ve never been able to get the GPU to work with previous versions either. Any comments / insight would grateful, eg Would upgrade to Lion improve my chance of getting GPU to work. Mac OS 10.6.8 2 x 2.66 GHz 6 Core Intel Xeon Nvidia Quadro 4000 for Mac (latest driver build 256.02.25f01) Maya 2012 Hotfix 3 V-Ray 2.2 Cheers ---
**Author:** ![t.petrov](https://avatars.discourse-cdn.com/v4/letter/t/c68b51/32.png) [@t.petrov](https://forums.chaos.com/u/t.petrov)\ **Post date:** [February 22, 2012, 12:47pm UTC](https://forums.chaos.com/t/rt-using-cpu-not-gpu/40447/2 "2012-02-22T12:47:30Z")
Hi, Can you post the log from the V-Ray standalone (the one in the popup up terminal)? /Teodor ---
**Author:** ![vlado](https://avatars.discourse-cdn.com/v4/letter/v/779978/32.png) [@vlado](https://forums.chaos.com/u/vlado)\ **Post date:** [February 22, 2012, 8:30pm UTC](https://forums.chaos.com/t/rt-using-cpu-not-gpu/40447/3 "2012-02-22T20:30:04Z")
Ah the Mac. Unfortuntely the OpenCL support on Mac OS X had way too many issues and we could not get it to work. I hope that for the next update we will have a CUDA version which tends to work better on the Mac. Best regards, Vlado ---
**Author:** ![Peter\_Grealy](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@Peter\_Grealy](https://forums.chaos.com/u/Peter_Grealy)\ **Post date:** [February 23, 2012, 12:21am UTC](https://forums.chaos.com/t/rt-using-cpu-not-gpu/40447/4 "2012-02-23T00:21:48Z")
Yes yes CUDA please, please, please! Octane works great using CUDA (sorry the mention that name here in this forum) I also just read that there is no official support for Open CL from Apple or Nvidia using the Quadro 4000 for Mac card? I remember way back when when Apple was renowned for its graphics capabilities, today they suck very badly.