Daily Trivia - USB-C Hub
Daily Trivia - USB-C Hub
Did you know not all USB-C Hub work the same? Even wonder why your USB-C hub can only output 4K@30Hz to your big giant monitor? Must I get the expensive USB-C hub or even thunderbolt hub so I can solve this lagging display issue?
Let me explain to you why.
To do high speed data transfer, USB-C actually can use 4 Lane of data pin, and for normal USB-C data transfer, 2 lane is more than enough to do 5Gbps (Gen 1) 10Gbps (Gen 2) or 4 lane to do 20Gbps (Gen 2x2). But this only applicable to data transfer (File transfer etc)
For display, USB-C use something call Display Port Alt Mode. Most cheapo USB-C hub out there have USB-C Chip that support Display Port 1.2 standard. DP 1.2 basically allow 4.32Gbps per lane video transfer.
So, if we only use the USB-C for display and nothing else, The chip can use all 4 lane and give u max video bandwidth of 17.28Gbps. Which is more than enough for 4K60Hz which use 12.54Gbps. However, if we want to use that same USB-C cable to data transfer as well, we will take away 2 Lane from the Video side, and now we left 8.64Gbps, which is not enough for 4K@60Hz display. That why all the early day USB-C hub only support 4K@30Hz which need only 6.18Gbps of video bandwidth.
What is the cheap solution for this then? Introduce Display Port 1.4 standard then. Compare to DP1.2, DP1.4 up the bandwidth per lane to 6.48Gbps. So if your USB-C Hub use the newer USB-C hub chip (PS186 DP1.4 to HDMI), you can solve this problem easily because even with only 2 lane, U have enough data to send 4K@60Hz to the display.
What the catch? Will it be more expensive?
Actually, the PS186 chip is almost the same price as the current USB-C chip out there, you can easily get the newer USB-C hub that support 4K@60Hz at the same price point.
But, the main catch is, your computer/Laptop need to support Display Port 1.4 standard to begin with.
For Intel PC/laptop, Only PC with 10th Gen Intel CPU onward support DP 1.4 output. Which mean most Intel Macbook doesn’t support it. If your laptop have dedicated GPU, high chance it support DP 1.4.
For Apple device, most Intel CPU without dedicate GPU model all doesn’t support DP 1.4. But all Apple Silicon one support, including M1 iPad.
Hope you learn something today.
