# Light Mix is preventing GPU rendering

**URL:** <https://forums.chaos.com/t/light-mix-is-preventing-gpu-rendering/113810>\
**Category:** Issues\
**Created:** [February 3, 2023, 5:45pm UTC](https://forums.chaos.com/t/light-mix-is-preventing-gpu-rendering/113810 "2023-02-03T17:45:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![paul\_rogers](https://avatars.discourse-cdn.com/v4/letter/p/aeb1de/32.png) [@paul\_rogers](https://forums.chaos.com/u/paul_rogers)\
**Post date:** [February 3, 2023, 5:45pm UTC](https://forums.chaos.com/t/light-mix-is-preventing-gpu-rendering/113810/1 "2023-02-03T17:45:54Z")

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Hi, has anyone else experienced this issue. When I add Light Mix as a render element I’m unable to render using GPU or CUDA. I get ERROR [V-RAY] [GPU light cache] Could not allocate buffer of size. Its very frustrating especially as it worked once and I found it really useful, now it wont at all.  
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**Author:** ![natalia.gruzdova](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/natalia.gruzdova/32/62693_2.png) [@natalia.gruzdova](https://forums.chaos.com/u/natalia.gruzdova)\
**Post date:** [February 6, 2023, 10:03am UTC](https://forums.chaos.com/t/light-mix-is-preventing-gpu-rendering/113810/2 "2023-02-06T10:03:37Z")

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Hello @paul_rogers ,

Please note that adding Render Elements will require more memory during render and the error you are getting indicates that you have run out of memory.

Regarding Light Mix are you adding it in the default mode Group by Individual Lights?

If yes, try changing it to Group Instances and track your memory in the VFB \> Stats.

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 ![LightMix.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/3/2/32117234167b29239c498ecf7c66b457e4e3118d.jpeg) ![VFB_stats.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/3/2/32cf476874f61530ccdcae50d0084c2b65f178c3.jpeg)

Apart from that please share your GPU model and what drivers do you have installed. ​