Lumion work specially on GPU (Graphic card processor), so you need to have at least a 2Gb memory called VRAM.
For rendering Lumion will only use Graphic processor, but when working on Lumion in editor it need rather than the GPU the computer processor. What mean, that when editing material, adding effects… Lumion ask for processor, system memory, and GPU. At least of 3GHz processor is needed to get better performance in editor.
Otherwise even if you have less then 3GHz it’s not a big problem, you can reduce editor quality resolution and you can continue working normal.
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