# Nvidia Index slower than VTK?

**URL:** https://discourse.paraview.org/t/nvidia-index-slower-than-vtk/2060
**Category:** Development
**Created:** [June 17, 2019, 11:21am UTC](https://discourse.paraview.org/t/nvidia-index-slower-than-vtk/2060 "2019-06-17T11:21:00Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![klayman](https://discourse.paraview.org/user_avatar/discourse.paraview.org/klayman/32/1597_2.png) [@klayman](https://discourse.paraview.org/u/klayman)
#### Post date: [June 17, 2019, 11:21am UTC](https://discourse.paraview.org/t/nvidia-index-slower-than-vtk/2060/1 "2019-06-17T11:21:00Z")

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Hello,

I am rendering a CT volume 600x600x300, trying both “Volume”, which I suppose is implemented by the VtkOpenGlVolumeMapper, as well as NVidia Index. I thought Nvidia Index would be the best performer, but on my Quadro M1000 it’s actually much slower than Vtk. Is this expected?