Problems with new Lenova PC's with intel 620 Graphics and 4 K monitors. I get max. 30 Hz in high resolution.

[JMulv]

Dear Intel

I can succesfully reach 60 Hz on the 4K screen mounted on my laptop PC. But I can't reach 60 Hz on my 4 K external monitor.

I have tried many different settings with no luck, and it looks like the Intel 620 Graphics driver is the ultimate problem (I am using the latest driver version). When I use the Microsoft basic graphics driver (by removing the Intel graphics driver), I can reach 4 K with 60 Hz on my hardware, but that is not an optimal solution for me.

When I connect my PC to my 4K monitor (using either DP through a dock or USB C direct) with the original Intel driver I get maximum 30 Hz in 4K. I can reach 60 Hz if I set the resolution to 1920 x 1080. The dropdown of the Intel graphics adaptor doesn't allow 60 Hz on any higher resolutions.

Hardware:

PC: Lenova Yoga 920 w. 7th gen. i7 processor with Intel 620 graphics.

Monitor: Acer PE320QK

Connection: USB-C to Thinkpad Dock 40A9. DP from dock to monitor.

Additional information:

I have attached information from the UHD graphic control panel.

BTW: I have two different new Lenova PC's (not both the same model) and two different 4 K monitors (again different models). All combinations fail to provide 4 K with 60 Hz independently of connection type. I don't see the problem as defective hardware.

Regards,

JMM

[n_scott_pearson]

The output of the processor is DisplayPort 1.2 compliant. This is easily able to support 4K@60Hz. Now, in order to support a HDMI connector, a LSPcon chip is used to make the protocol conversion. If this is an older LSPcon chip or the firmware for this chip is not the latest, then it may not be able to support 4K@60Hz. You need to talk to your laptop vendor and find out if the LSPCon chip that they used is capable and whether a firmware update is necessary.

Hope this helps,

...S

[JMulv]

@n.scott.pearson​ 

Thank you, I really appreciate your fast reply. However, I'm not sure your qualified answer applies to my Lenova Yoga 920. It has the latest firmware installed and it has no HDMI output (and neither does the dock). Also I can reach the full 4 K 60 Hz with the same hardware when I'm not using the Intel graphics driver. I will contact my laptop vendor if everything fails, but I have high hope for this forum.

[n_scott_pearson]

Ah, I see what you are saying; I read it wrong.

The reports you attached both list support for 3840x2160 at 60Hz as being available. Are you saying that the Control Panel does not show this setting and/or will not allow you to pick this setting? The solution would normally only limit the output to 30Hz if it saw a throughput issue.

...S

[JMulv]

In the Intel graphics control panel my maximum frequency is limited to 30 Hz when the resolution is anything higher than 1920x1080. This is also true when I open advanced screen settings and look at valid settings (see picture below in Danish).

[n_scott_pearson]

Hhmmm, I wonder why the report shows the option as being available yet won't offer it for use. Well, this is beyond my ken; the Intel Customer Support folks will need to look into this (would that be you @Bryce@Intel​?).

Sorry,

...S

[Wanner_G_Intel]

Hello JMulv, Your processor graphics supports 4K at 60Hz since you can successfully select this configuration on your built-in display. Also, based on the specifications of your processor graphics, you should be able to connect an external monitor and get up to 4096x2304@60Hz through DP. This is most likely a hardware limitation. In other words, your system manufacturer may have limited the native video resolutions and refresh rates supported by the computer when connecting external monitors. Processor graphics https://ark.intel.com/content/www/us/en/ark/products/122589/intel-core-i7-8550u-processor-8m-cache-up-to-4-00-ghz.html To better address this issue, we recommend contacting your system manufacturer for more information on the system design. Wanner G. Intel Customer Support Technician Under Contract to Intel Corporation

[JMulv]

Hi n.scott and WannerG

Thank you both for your time and thoughts. This is a strange case as Lenovo should have a number of professional users with the same problem. As mentioned, I have two new Lenova PCs (the other is an X1 carbon) with the same problem on two different external monitors. Anyway I will contact Lenova from here.

Regards ...