HD620 DPalt > 4k@60?

[idata]

I have a samsung U28E590D monitor(tested seperately with discrete graphics at 4k@60), a kensington SD4600P USB-C dock, and a Lenovo Yoga 910, which has an i7 7500U and HD620 graphics.

I am unable to get 4k@60 resolution to my monitor. I can only get 4k@30. On paper this should all work, so Im trying to find the culprit. I have upgraded the firmware on the kensington dock, and also tried their suggestion of plugging things in in a certain order to prioritize bandwidth. Ive also manual installed the latest hd620 drivers, and tried every display setting available, except for the custom resolutions.

I just contacted lenovo support, and they claim it is a limitation of the graphics hardware. So the question is, will the HD620 output 4k@60 via DisplayPort Alt over a USB-C dock? Or is it limited to 4k@30, perhaps a limitation specific to the lenovo yoga 910?

[idata]

Hello randay,

After an extensive research I was able to confirm with the manufacturer of your SD4600P USB-C™ Universal Dock with Power (Kensington) the following detail:*4K Ultra HD resolution (4096x2160) to single monitor at 60Hz via HDMI or DisplayPort, or dual monitors at 30HzThis is the reason why you see this decrease in the refresh rate to 30Hz with 4K; the Dock counts the laptop and the monitor as Dual display.You can confirm this detail at the manufacturer website; under "Features":https://www.kensington.com/us/us/4491/k38231ww/sd4600p-usbc-universal-dock-with-power Kensington (SD4600P USB-C™ Universal Dock with Power)I am looking forward to hearing from you.Regards,Angie

[idata]

Thank you for looking into my issue.

I believe the details of the sd4600p dock are referring to single monitor or dual monitor plugged into the dock. and does not count the integrated laptop monitor in the spec?

I am also able to pick single display in the intel display settings, and only display to the external monitor via the sd4600p dock's displayport OR HDMI output. in this situation the laptop display is off, and i am still only able to acheive 4k@30.

just to note i am also able to drive the laptop display at 4k@60, the external monitor at 1440@60 via displayport on sd4600p, and my TV at 1080@60i via the HDMI on the sd4600p. for a total of three displays in extended display mode.

here are the max resolutions i am able to acheive:

single display:

laptop 4k@60 OR external 4k@30

dual display:

laptop 4k@60 and external 4k@30

triple display:

laptop 4k@60, external 1440@60 and TV 1080@60i (my TV is 1080i max and so it is limiting that display resolution, probably will go to 1440@60?)

[idata]

Hello randay,

I will do a second research in regard to your concern.As soon as I have further details I will inform you.Best regards,Angie

[idata]

Hello randay,

In regard to your concern, could you please install the latest graphic driver:https://downloadcenter.intel.com/download/26404/Intel-Graphics-Driver-15-45-?product=96551 Intel® Graphics Driver [15.45] (Version: 15.45.10.4542 (Latest) Date: 11/9/2016 )Is the issue persist, could you please let me know how many memory sticks are you using? And if it is possible the model?Hope I can hear from you soon.Regards,Angie

[idata]

Hello randay,

I would like to know if the information provided to you was able to solve your concern?In case if you need further assistance, could you please let me know how many memory sticks are you using? And if it is possible the model?Hope I can hear from you soon.Regards,Angie