logo

Live Production Software Forums


Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Options
Go to last post Go to first unread
dundurs  
#1 Posted : Thursday, June 21, 2012 6:41:46 AM(UTC)
dundurs

Rank: Advanced Member

Groups: Registered
Joined: 3/24/2011(UTC)
Posts: 273

Thanks: 8 times
Was thanked: 45 time(s) in 22 post(s)
I have come across a strange situation on Dell Vostro 3750, which uses integrated Intel HD Graphics 3000 and nVIDIA GeForce GT 525M (GF108M, 1GB DDR3 SDRAM, 96 cuda cores) processor. Both graphics processors work simultaneoulsy, and its is possible to choose which adapter will be used for a specific application by holding shift key, pressing right mouse button and choosing "Run with graphics processor".

If I choose to run vMix with integrated Intel HD graphics processor, I get around 4ms render time versus 16ms when using nVIDIA processor. Any idea why vMix rendering performs worse with a better graphics processor?
admin  
#2 Posted : Thursday, June 21, 2012 11:05:07 AM(UTC)
admin

Rank: Administration

Groups: Administrators
Joined: 1/13/2010(UTC)
Posts: 5,149
Man
Location: Gold Coast, Australia

Was thanked: 4145 time(s) in 1490 post(s)
Hi Dundurs,

From the testing I have done on these dual-graphics laptops the laptop screen appears to be directly connected to the Intel HD Graphics.
When you select the "Run with graphics processor" mode the driver copies the rendered data from the GeForce to the Intel HD Graphics which causes a jump in render time.

See below for more technical details:

http://en.wikipedia.org/wiki/Nvidia_Optimus

Regards,

Martin
vMix
dundurs  
#3 Posted : Thursday, June 21, 2012 11:36:39 AM(UTC)
dundurs

Rank: Advanced Member

Groups: Registered
Joined: 3/24/2011(UTC)
Posts: 273

Thanks: 8 times
Was thanked: 45 time(s) in 22 post(s)
Thanks for explanation. Does render time has anything to do with decreasing video motion or it just describes latency?
In other words is there a point to try to move from 20ms to 0ms render time by using alternative video adapters in some cases?
admin  
#4 Posted : Thursday, June 21, 2012 12:06:19 PM(UTC)
admin

Rank: Administration

Groups: Administrators
Joined: 1/13/2010(UTC)
Posts: 5,149
Man
Location: Gold Coast, Australia

Was thanked: 4145 time(s) in 1490 post(s)
Render time measures the time it takes for the graphics card to render one frame of output.
In general any value under 25ms will allow full motion of up to 30fps.
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.