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I am trying to get my new 4k monitor running at 60hz refresh rate. At the moment I have a laptop with a micro HDMI port that is most likely HDMI 1.4, since the xrandr outputs:
HDMI-1 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 698mm x 393mm
3840x2160 30.00* 30.00 25.00 24.00 29.97 23.98 29.98
1920x2160 59.99
1920x1080 60.00 60.00 50.00 59.94
...
Are there any hopes of running at 60hz short of buying a new laptop?
I was considering this dongle:
to connect from USB 3.0 to a DisplayPort. Event the seller says:
Expand your work space by up to two external DisplayPort monitors via USB 3.0, USB C or Thunderbolt 3 Port. The adaptor supports 1x 5 K resolution up to 5120X2880 @ 60Hz or 2x 4 K resolution up to 4096 x 2160 at 60 Hz addition audio signal
However, for me, the numbers don't add up. If you would like to have a 32bit color depth with 8 megapixels times 60 frames, you get a required bandwidth of 15 Gbit/s, yet USB 3.0 has only 5 Gbit/s.
Are my calculations correct, or am I missing something? Is the pc sending out the color of each single pixel at each single frame, or just the pixels that changed? Is there perhaps some in-monitor firmware decompression? Is this just false advertising?
Martin Drozdik
Posted 2019-01-21T14:34:42.203
Reputation: 145
https://i-tec.cz/en/produkt/u3dual4kdp-2/ – Tetsujin – 2019-01-21T16:35:15.357
@Tetsujin - These are the specs that the questioner quotes, but they don't explain his arithmetic, which underestimates the quandary, since the interface claims to support two independent 4K displays at 60Hz with their audio channels. – AFH – 2019-01-21T18:00:39.750
1@AFH - I was just linking to the manufacturer's main page on it - I wasn't trying to work out the numbers independently ;) – Tetsujin – 2019-01-21T18:03:40.540