04-08-2019 04:01 PM - edited 04-08-2019 04:06 PM
I have a Yoga X380 (LJ model) which I'm trying to get to display 4k (3840x2160@60hz) on my Iiyama GB2888UHSU monitor via HDMI (if possible). I read the specifications of the laptop and I know that via the built-in HDMI it can't do 60hz, but manages only 30hz. I know I have to use the Thunderbolt/USB-C port and indeed I can, and have, but only at 30hz. I know the monitor only has a single HDMI port (Port 1) which can do this refresh rate, that's what I'm using.
I have tried a couple of dongles (but not the Lenovo one, coming on to that!) and verified my HDMI cable and dongle by using a PC and my Galaxy S9 - both happily display 3840x2160@60hz no problem at all via the same monitor port, cable & dongle that won't do 60hz via the Yoga) . Regardless of what I do I can't get the Yoga to do it. The mode is available but when I select it I get "no signal" and then the display reverts back to @30hz when it times out and the setting isn't confirmed.
I know the Thunderbolt port can do this, way more than this actually. Indeed there is a listed compatible Lenovo USB-C to HDMI dongle (Part 4X90R61022 - https://pcsupport.lenovo.com/gb/en/solutions/PD500273). The specification claims this supports the required 3840*2160@60hz. Why have I not purchased this yet you ask? Well, I got the laptop with a USB-C charger (work device) so I don't have another USB-C port to use (until I buy a dock I wouldn't be able to charge & use the monitor, see below)
My questions are twofold
1) Will that dongle work? I know it should but has anyone got one and verify it works at 60hz?
2) Which dock should I get so I can use USB-C to connect to the dock, charge the laptop and then how to connect to the monitor? I don't have DP free on the monitor - that's used by something else.
I have looked at the Thunderbolt Dock ( Part 40AC0135US) but confusingly although the laptop and thunderbolt port support the required resolution, the onward connection from the dock (Dock HDMI -> monitor) doesn't appear to support 60hz. Is there a dock that does what I need does anyone know?
One last question, would the USB-C Dongle above allow the connection from the dock to the montor and work?
Many thanks - I really have tried googling the hell out of this, spent a bunch of time on this forum and can't see anyone with this particular requirement or issue. More than happy to be pointed at the docs for this if I've missed something but I'm all out of ideas!
Many thanks for reading!