rolling back to sierra is no option for you ?

no, i have a legacy partition already for using final cut pro studio, the rest of the system needs to be up to date. also, i am sure there must be a solution in high sierra, too, since there is no technical reason for the restriction.

ok. I know many MAC users use an app like SwitchResX to make a custom resolution on MAC OS …

will check with R&D if they knwo a work around of some sort, but as often with new MAC OS Updates it often takes until a next update until (most) issues are fixed …

great, thanks!

no problem just hope these High Sierra issues will be resolved soon …

did your R+D find out anything?

thx

never mind.

just zapped NVRAM. and this actually brought back 4k@60Hz. great!

thank you for your support! sorry to keep you busy.

no problem, good to hear it is working for you 🙂

With RDM or SwitchResX I do not see option for 3840×2160 @ 60HZ. Any ideas why?

zap NVRAM. if your mac can do 60Hz, it will appear. otherwise, it most likely cannot.

Hi, 

Zapping NVRAM did not work for me (macOS High Sierra 10.13.4, MBP 15-inch, Mid 2014 with nVidia 750M). 
Whatever I do, I can not get 4K 60Hz (active adapter 1.2 DP to 2.0 HDMI). 
I checked the cable, playstation can output 4K 60Hz no problem. 
I tried both RDM and SwitchResX – none shows 4K 60Hz. 

Any other ideas what I might do?

Thanks, 
Mario

your MBP does not support 4k@60Hz. check the specs. sorry.

Hi, 

It definitely supports 4K at 60Hz over DisplayPort. 
I was connected with miniDP -> DP cable to a 4K monitor with 60 Hz no problem. 
Now I am trying same thing, but using Club3D adapter miniDP -> HDMI. 

I did manage to get 60Hz in macOS at the end, but screen is black. 
At one point I actually did get image (monitor was showing 4K 60Hz) but image was very stretched.

I am also trying to use Denon X2400H as intermediator (with enhanced HDMI enabled), but no luck with getting image at 60Hz.

Hi mblataric,

Please try first without the Denon receiever in between.
FW version is mentioned on the label of the Adapter should be someting like “V7.55”.

In general

• Setup

Setups with TV’s normally work best by making a custom resolution, 3840*2160 at 60 Hz with Timing Standard set to CVT-RB (Reduced Blanking).

(For setups with Monitors Timing Standard can remain on “auto”.)

On most TV’s you will need to do some settings like “Enhanced Mode”/ “PC-Mode” and/or “UHD Color” for the HDMI 2.0 port in use. 

Please make sure the HDMI port of the Screen/TV supports 4K 60 Hz, often not all HDMI inputs support that.

 Pleas make sure to use a Premium HDMI 2.0 cable capable of doing 4K 60Hz / 18Gbps

• Custom Resolution

To be able to generate such a Custom Resolution you will need an app like SwitchResX since MAC OS does not provide such settings.

Should be something like this, please do make sure to have it set to “CVT-RB”

You might need to make a new user, certainly if you already had it installed before.

Hi, 

Ok, it seems there are some problems with custom resolutions on Dell 2715Q. 
However, this is not important because I was using 2715Q only to test adapter (without success), because there is no point to force 4K60Hz over HDMI on 2715Q since it has DisplayPort.  

Purpose of the test was weather or not this scenario will work with TV and can I use TV as my monitor. 
Eventually I did a test with my friend on Sony 55XE9005 using custom resolution and test was a success – I got 4K at 60Hz using CAC-1170.

I do not know why 2715Q refuses 4K60Hz over adapter (it does accept 4K60Hz from PS4 Pro connected through Denon X2400H) – I suspect the issue is with timers – however, I do not want to waste more time on this since I now know adapter is working on TV set I plan to purchase. 

Thanks for support, 
Mario

It did not work on your Dell 2715Q because the monitor does not support 4K 60Hz on its HDMI input, that only support 4K up to 30Hz.

Hi, 

You have incorrect information. 
https://dell.to/2HEi1j1

Also, I have PS4 Pro connected through Denon X2400H to 2715Q on HDMI port and I get 4K at 60Hz. 
Here is the screenshot:

Regards,
Mario

ok sorry about that.
I saw that info on the product page specs on the Dell website 
http://www.dell.com/en-us/work/shop/dell-27-ultra-hd-4k-monitor-p2715q/apd/210-adof/monitors-monitor-accessories

they must have updated it since then, did you check for latest software for the screen?

Hi,

I did not, but as I said, it does not really matter because the only purpose was to test adapter – which I successfully did with Sony TV which I plan to use.
But I do not believe this problem has anything to do with the adapter, but rather macOS quirks (god forgive :-)) or incorrect timing settings since monitor is obviously quirky as well on HDMI. 

Regards,
Mario

ok thanks for the feedback