# Blender on new iMac with Nvidia GT 640M **URL:** \ **Category:** Technical Support\ **Created:** [December 29, 2012, 3:52am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752 "2012-12-29T03:52:37Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![tahseen](https://blenderartists.org/user_avatar/blenderartists.org/tahseen/32/11783_2.png) [@tahseen](https://blenderartists.org/u/tahseen)\ **Post date:** [December 29, 2012, 3:52am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/1 "2012-12-29T03:52:37Z")
Dear All, Blender is not able to detect the Nvidia GT 640M and thus am not getting the GPU rendering. Please help Thanks ---
**Author:** ![Richard\_Marklew](https://blenderartists.org/user_avatar/blenderartists.org/richard_marklew/32/4458_2.png) [@Richard\_Marklew](https://blenderartists.org/u/Richard_Marklew)\ **Post date:** [December 29, 2012, 4:00am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/2 "2012-12-29T04:00:58Z")
\*\*\* Moved thread from Discussion to Support \*\*\* ---
**Author:** ![bernardosgr](https://blenderartists.org/user_avatar/blenderartists.org/bernardosgr/32/24310_2.png) [@bernardosgr](https://blenderartists.org/u/bernardosgr)\ **Post date:** [December 29, 2012, 6:40am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/3 "2012-12-29T06:40:29Z")
640M on an iMac? Aren’t iMacs desktops? aren’t you talking about a macbook or something like that? Maybe you should update the drivers, check if it is recognized, I don’t know a lot abut this subject, but drivers might be your problem. ---
**Author:** ![tahseen](https://blenderartists.org/user_avatar/blenderartists.org/tahseen/32/11783_2.png) [@tahseen](https://blenderartists.org/u/tahseen)\ **Post date:** [December 29, 2012, 8:58am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/4 "2012-12-29T08:58:31Z")
Am talking of new iMac. By the way I figured out it was because of missing CUDA driver and toolkit. And also gcc. I installed all of it so now I see GPU Compute but then when I start the realtime render in viewport, I get this error CUDA error: Launch failed in cuCtxSynchronize() ---
**Author:** ![Jonothewright](https://blenderartists.org/user_avatar/blenderartists.org/jonothewright/32/20361_2.png) [@Jonothewright](https://blenderartists.org/u/Jonothewright)\ **Post date:** [December 29, 2012, 12:40pm UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/5 "2012-12-29T12:40:43Z")
iMacs are desktops in appearance only. _All_ of the parts inside them are laptop parts. Yet people keep buying them and complaining when they don’t work well with Blender. ---
**Author:** ![tahseen](https://blenderartists.org/user_avatar/blenderartists.org/tahseen/32/11783_2.png) [@tahseen](https://blenderartists.org/u/tahseen)\ **Post date:** [December 30, 2012, 9:45am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/6 "2012-12-30T09:45:27Z")
Jonothewright: Wish you could speak about something helpful. Initially, I didn’t have CUDA driver installed. I installed CUDA 5.0 but then Blender was crashing I resolved the issue all by myself. I had installed CUDA 5.0, which was not supported by Blender 2.65a on Blender site. I download more recent build and everything worked ---
**Author:** ![Jonothewright](https://blenderartists.org/user_avatar/blenderartists.org/jonothewright/32/20361_2.png) [@Jonothewright](https://blenderartists.org/u/Jonothewright)\ **Post date:** [December 30, 2012, 11:07am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/7 "2012-12-30T11:07:50Z")
I was replying about something helpful. What I wrote was both entirely true and directed at bernardosgr who asked if you meant the iMac was actually a laptop based on the mobile processor. I should have included a quote from his post. ---
**Author:** ![obkcaptain](https://blenderartists.org/letter_avatar_proxy/v4/letter/o/9dc877/32.png) [@obkcaptain](https://blenderartists.org/u/obkcaptain)\ **Post date:** [December 31, 2012, 1:49am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/8 "2012-12-31T01:49:40Z")
So…Can anyone help me? I’m using an iMac with ATI Radeon as graphic card wich isn’t recognized from Blender. As far as I know, Neither CUDA, nor possibility to use Cycles Render speedly. Only CPU. At system tab into “User preferences” it replay “None” for graphic device… Must I shift to a PC? Currently, I can use Blender Render, but in the next… Please: somebody can explain (step by step, please) What can I do? Thanks and Have a happy new year ---
**Author:** ![m9105826](https://blenderartists.org/user_avatar/blenderartists.org/m9105826/32/6760_2.png) [@m9105826](https://blenderartists.org/u/m9105826)\ **Post date:** [December 31, 2012, 3:24am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/9 "2012-12-31T03:24:39Z")
ATI/AMD support is currently on hold for Cycles. It will remain so until AMD can fix their OpenCL compiler. ---
**Author:** ![place57](https://blenderartists.org/user_avatar/blenderartists.org/place57/32/12530_2.png) [@place57](https://blenderartists.org/u/place57)\ **Post date:** [December 31, 2012, 5:33am UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/10 "2012-12-31T05:33:45Z")
> [@obkcaptain](#): > > So…Can anyone help me? > I’m using an iMac with ATI Radeon as graphic card… I too have that same configuration. My suggestion is to put 16 gig of ram into your imac, then start saving money fir a different computer. I am looking at the new macbook pro fully loaded. This gives me the NVIDA card I need for (useful) cycles. My imac will then become a very expensive second monitor… ---
**Author:** ![mskap123](https://blenderartists.org/letter_avatar_proxy/v4/letter/m/b19c9b/32.png) [@mskap123](https://blenderartists.org/u/mskap123)\ **Post date:** [December 31, 2012, 1:16pm UTC](https://blenderartists.org/t/blender-on-new-imac-with-nvidia-gt-640m/560752/11 "2012-12-31T13:16:10Z")
> [@tahseen](#): > > Jonothewright: Wish you could speak about something helpful. > > Initially, I didn’t have CUDA driver installed. I installed CUDA 5.0 but then Blender was crashing I resolved the issue all by myself. I had installed CUDA 5.0, which was not supported by Blender 2.65a on Blender site. I download more recent build and everything worked Can you point me to the link where you downloaded the more recent build? I can’t seem to find it.