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Watchpax4 Multiple 4K Outputs?

Watchpax4 4k Multiple outputs screen taring

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#1 erichpeters

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Posted 05 December 2017 - 09:11 PM

Has anyone used a WatchPax4 system to drive multiple [email protected] outputs into LED processors? 

Being that a WatchPax cannot be genlocked, did you have any issues?


I am looking at a scenario where we would be outputting 4 x [email protected] from a Watchpax into either a Dual E2 setup and then to 4k LED processors, or directly from Watchpax into 4k LED processors.  Pixel space is setup as 15360x2160.  Screen tearing is what I am most concerned with since I will be dealing with a 0 pixel gap between outputs to the LED processors.  


Any thoughts or words of wisdom?

Thank you in advance!





#2 RBeddig


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Posted 08 December 2017 - 10:26 AM

According to our tests the WATCHPAX 4 outputs are frame locked. We have tested this with 4x 1080p50/60 on 4 LED processors. WATCHPAX 4 does of course not support any cross server sync.


BUT, I doubt, that you will be able to play out 4x [email protected] with WATCHPAX 4. The unit uses two SATA-3 SSDs in RAID 0 configuration. We have seen playouts of 4x 4K (UHD)@30fps but not at 60fps. Even a large 19" system can run into problems here since the FirePro graphic cards do not support 4x [email protected] You can usually use two or three outputs with that resolution but not all of the outputs. It's related to the internal design of the graphic cards and the graphic card drivers.

#3 Miro



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Posted 13 December 2017 - 12:04 AM

Hi, with the performance updates in WATCHOUT 6.2 it's now possible to play 4x [email protected] using HAP.


We tested this last week with filmed content (less compression than animated/CGI content). At average we pulled 785 MB/sec from the SSD drives (Max read speed of ~1050 MB/sec). The problem in this case is that you will fill the 1 TB drive very quickly. 


The Nvidia GPU will automatically genlock the outputs if the output timing of all ports are equal. We measured the offset between the outputs using an oscilloscope and the WATCHPAX4 outputs where better synchronized (a few nanoseconds) than outputs on a AMD FirePro 7100 + S400 card. 

Also tagged with one or more of these keywords: Watchpax4, 4k, Multiple outputs, screen taring