The compatibility challenges with both USB-C and DP hasn’t stopped you from making other USB-C and DP adapters.
Anyway, I’ve tried the Sunix UPD2018 card in one of my GA-Z170X-Gaming 7 motherboard’s PCIe 3.0 x1 slots. Sadly, my GA-Z170N-Gaming 5 motherboard doesn’t have a spare PCIe slot, which is one of the reasons for my suggestion of an external adapter.
The UPD2018 seems to work as advertised. I was able to use various USB devices (1.1, 2.0, 3.0, 3.1) and USB-C display adapters (2 lanes=4K30Hz, 4 lanes=4K60Hz). I don’t have any combination USB 3.1+DisplayPort (2 lanes) devices to test.
I was able to use the Plugable USBC-VGA adapter (usbc-vga) to output from one of my Nvidia graphics card’s DisplayPort ports. The usbc-vga supports 2048x1536@73Hz (330 MHz) but for some unknown reason only 1920×1200@60Hz is advertised?
The UDP2018 uses the following chips (in addition to the ASM1142 USB 3.1 Host Controller chip mentioned in the product description):
- TUSB1046-DCI USB Type-CTM DisplayPortTM ALT Mode 10 Gbps Linear Redriver Crosspoint Switch
- CYPD4225-40LQXI EZ-PDTM CCG4 dual port DRP controller
- TPS54427 4.5-V to 18-V Input, 4-A Output Single Synchronous Step-Down Switcher With Integrated FET
- HD3SS3212x Two-Channel Differential 2:1/1:2 USB3.1 Mux/Demux
It also has a 4 port USB 2.0 hub connected to one of the ASM1142’s USB 2.0 ports. One of the hub’s outputs is for one of the USB-C outputs. Another hub output is for an interface used for firmware updates. This is probably not for the ASM1142 chip which would have firmware updated from PCIe.
5) CY7C65634 HX2VLTM Very Low Power USB 2.0 Hub Controller
6) CY7C65211 USB-Serial Single-Channel (UART/I2C/SPI) Bridge with CapSense® and BCD
7) HT24LC02 CMOS 2K 2-Wire Serial EEPROM
8) MX25L2006E 2M-BIT [x 1/x 2] CMOS SERIAL FLASH
9) etc.