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opentv
1 Nickel

Alienware 18 - not outputting 4k Resolution reliably

Just got the Alienware 18 with two NVidia GTX 780M's in SLI. Been trying to output 4k resolution but the image flickers off and on intermittently. I've tried various refresh rates with no luck. I'm using the single HDMI output port on the laptop. Tried different brands of cables (and realized that one of them works better than the others). Updated to the latest drivers from NVidia as well.

The image flickers most predictably when going from a full screen 4k video (using VLC) to minimizing it back to a window. The  monitor loses sync and the monitor shows a message that the signal was lost. The signal comes back shortly after, but this isn't ideal for this top-notch laptop and setup. Any help would be greatly appreciated!

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3 Replies
skitzo213
1 Copper

RE: Alienware 18 - not outputting 4k Resolution reliably

hey, just thinking out loud did you try a 4k hdmi cable. most cables are rated for 1080, http://www.amazon.com/dCables-High-Speed-Cable-Ethernet/dp/B005AZSDCC like you said before different cables worked differently. the cable needs to be able to able to carry 4x the resolution. try one of these cables out.

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opentv
1 Nickel

RE: Alienware 18 - not outputting 4k Resolution reliably

We just tried a whole slew of cables from Monoprice. I can confirm, all hdmi cables are not created equally when it comes to this much data spewing across the cables. However, sadly to say, the video feed is still disrupted when a 4k video goes from full screen to window-mode. The display loses sync and then comes back on after a brief second. We also tested it on another 4k screen, however, and found that it does NOT flicker. So the combination of screen type, cable, and computer hardware seems to have a big impact. Thanks for the reply! Unfortunately, our main 4k setup still isn't working the way we want it to. 

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ShadowsNight
1 Nickel

RE: Alienware 18 - not outputting 4k Resolution reliably

Hey man, Just so you know, you'll need a HDMI cable with a high enough transfer rate to use 4k reliably though it looks like anything higher than 10.2Gbps is over the hdmi 1.4 threshold, to be honest though, I can't even get mine to work at all..... but yeah, check your cable rating, could be that.

 

Also, not sure if your aware but hdmi 1.4 can't effectively run 4k at a higher refresh rate that 30MHz, have you tried running it at 24MHz?

It could be that your tv just can't run that resolution at that refresh rate, just like running the Nintendo Game Cube at 60MHz on a 50MHz tv.

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