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Theoretically: If I have a HTPC or Nettop with HDMI-out connected to a HDMI-splitter (one to many) and connect this to a TV and at least one other display, will they all be vertically synched (without image tearing) no matter how many displays there are? How do I know if a splitter supports vsynch? Do all?

Is it normal for a HDMI-splitter to allow cloned mode or is that something other than a standard splitter? I want the same image on all displays and I need all to be vsynched. Also the displays may run with different refresh rates but the will all have 1080p-resolution if that matters.

Is this possible?

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Vertical synchronization simply locks the software running on the GPU from rendering more frames per second than the display updates (i.e. using Vsync with a 60 Hz display will limit your FPS in any application that is Vsync'd to 60 FPS). This is what prevents tearing, and is irrelevant from an HDMI perspective.

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So I won't get even a stationary tear at some line if all screens run at 60 Hz? Because that's the problem I have now using a all-in-one-pc with hdmi-out. Only the primary display is tear-free and the secondary (TV running at same 60Hz) has a stationary tear. I'm hoping using a Nettop with a HDMI-splitter will solve the problem completely without any kind of tear on any of the displays. Is that so? – Andreas Zita Jan 18 '13 at 15:04
How are they set up, as a cloned display, or as separate displays? That really depends on what graphics card you have, and if the drivers allow different monitors to be synchronized to different vsync rates. – Breakthrough Jan 18 '13 at 15:06
Intel HD 4000 with cloned displays. But I'm thinking of replacing this AIO with a Nettop with HDMI-splitter if that Will be a solution. – Andreas Zita Jan 18 '13 at 15:27

I've tested this a bunch recently and using an HDMI splitter solves the tearing problem. I have a motherboard with dual HDMI out and Intel 4000. When using cloned mode, the secondary monitor has horrible tearing, but with several different HDMI splitters I've tried and single monitor mode, I have no tearing on either monitor.

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