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I have XPS 15z with Nvidia GT 525M and Intel graphics cards running using optimus technology. Currently, when I start xbmc it runs using the "intel" driver. And it runs totally fine but I would like to know if there is a difference when running xbmc on intel or nvidia ?

If yes, how can I run xbmc on nvidia ?! I tried "optirun xbmc" but it became sluggish and unusable.

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if you run: vblank_mode=0 optirun xbmc OR vblank_mode=0 primusrun xbmc How's that? – aXept Jun 7 '13 at 16:13
@aXept Could you explain more what the difference does it make running with or without for each command? – GuySoft Jun 8 '13 at 11:00
@aXept It works :D ... can u please explain what is "vblank"? and also could you also point out if it will enhance the video quality when xbmc is running using optirun (nvidia card instead of intel)?! – TeFa Jun 8 '13 at 15:36
up vote 1 down vote accepted

If you run: vblank_mode=0 optirun xbmc OR vblank_mode=0 primusrun xbmc How's that?

vblank_mode=0 is just for the graphic card not to set a default refresh rate on the screen (monitor/tv). It set the best possible refresh rate. It MAY make tearing because it sets the refresh rate higher then your monitor supports.

For the "optirun" vs "primusrun" I found this information:

Primus brings better performance and less power consumption when using Bumblebee, by replacing VirtualGL. According to the Bumblebee G+ page, this has the following advantages over the optirun (VirtualGL) solution used by default in Bumblebee:

- Less overhead (better framerates) and cleaner solution (no networking or compression involved at all)

- Fixes the "bug" that causes Bumblebee to shut down the GPU too early sometimes (no more need for the "optirun bash" workaround)

- Less buggy/glitchy, easier to debug

- Only uses/starts secondary GPU for OpenGL parts of applications - everything else remains on your main GPU (power savings)

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