Dual-Monitor performance with two video cards

[WKjun]

Hello!

I am about to implement this highly anticipated new version soon!
Previously I have used two monitors where just one of them is shared (fullscreen) and the other used locally. It is used as a kind of DJ desk where I can modify the playlist on one screen while music videos are played back on the other which is streamed over 1Gbit LAN to the actual seen screen. Therefore video playback is just at 1024x768 (PAL & NTSC framerate), but in realtime (U2 mode).

As far as I can recall a previous statement here, it is best to use a seperate video card for the second monitor. Is that (still) so?
The other question is, if the primary video card is pretty fast, would it make a positive difference using a second but rather slow video card? Or does it only matter if both screens are streamed?

• Radeon RX 590 (8GB)
  Radeon RX 550 (2GB)

Kind regards,
Wilhelm

[Rudi De Vos]

**With 2 cards, you capture parallel
**With a single card you need to capture screen A followed by screen B
If one of the screens is static, you loose a few ms while you wait for changes
Having same small screen with changes (like a screensaver preview) on the static give a few extra FPS
It's faster when the screen change on both monitors..

Test video card
HD 630 intel, that's a little slower then the RX 550

Settings encoder u2 -> now called video
set cpu to 100 ( server option): This not only set the max cpu that can be used by vnc but also
switch to fast capture.

With the HD 630 we get 30 FPS with single monitor.
As dual monitor i use a GTX 1050, for video it's around 28FPS
resolution 1920x 1200
We use Youtube 60FPS test video's

Normal you should easy get 40 FPS with 1024x768 if your video source can deliver it.

Natural it also depend on the bandwidth and used media.

[WKjun]

Thanks Rudi for clearing things up and share some fundamental aspects of its behavior!

Although it seems logical that those screens which get captured should be on the faster card, it makes me wonder what parts of modern graphics cards are used in the capturing process that could make such a big difference.

My impression is that since after the 1990s, where 3D rendering and GPUs took place, 2D performance is as fast as can be and does not make a difference anymore for working on Windows desktop, 2D games and video playback. In fact modern cards don't even ramp up clock frequencies a lot while doing anything "2D".

[Rudi De Vos]

win 10 Capture is done using directx.