Late 2013 iMac ~4K@60

[Rumpot]

My monitor is 3840x1600( has DP, mDP, & HDMI 2.0 inputs)
Apple is very vague about what cable is needed to drive this from my iMac
https://support.apple.com/en-us/HT206587
Single-Stream (SST) displays
Most single-stream 4K displays are supported at 30Hz operation.

With OS X Yosemite v10.10.3 and later, most single-stream 4K (3840x2160) displays are supported at 60Hz operation on the following Mac computers:

• MacBook Pro (Retina, 13-inch, Early 2015) and later
• MacBook Pro (Retina, 15-inch, Mid 2014) and later
• Mac Pro (Late 2013)
• iMac (27-inch, Late 2013) and later
• MacBook Air (Early 2015)

Will any 1.2 compatible mini display port cable work? Do I need an mdp-->active HDMI 2.0?
There so not seem to sell any cable/adapters to do this in the store.
Anyone have any experience with this?

 

[Fishrrman]

I would try a minidisplayport-to-minidisplayport first.

If that doesn't work, try minidisplayport to HDMI 2.0 (active converter).

 

[Rumpot]

So I tried a miniDP to DP. The external screen resolution will not go above the iMac default of 2560-1440
It does recognize the monitor(Acer XR382CQK ) and show a color profile in colors tab, I just cannot change the rez to 3860x1600

Is there so other setting to check to allow for different resolution on the external screen?

 

[Rumpot]

SwitchX will only let me get 30hz
SwitchResX4 - Acer XR382CQK:

Resolution: 3840 x 1600 @ 30 Hz
Pixel Depth: 32-Bit Color (ARGB8888)
Mirror: Off
Online: Yes
Rotation: Supported
Connection Type: DisplayPort
Television: Yes

Does anyone know what I can do to get 60hz? Is apple document listed above just flat out wrong that the Late 2013 iMac can do 3840x2160@60. Im a trying a smaller rez and it just won't work. Do I need to run the pixel clock patch? I thought that patch was to go over 165Mhz, the 3840 x 1600 @ 30 Hz is running @194.81Mhz.

How to I disable Television: Yes

Any ideas, anyone??

 

[Fishrrman]

I'll guess that as a last resort, you could try this:

https://www.amazon.com/Club3D-Mini-...bl-20&linkId=379ef539efb9286895ddf45f1be804b1

It's a minidisplayport-to-HDMI 2.0 "active" adapter/convertor.
Take the time to read ALL the reviews (at least the Mac-pertinent ones), and ALL of the questions and answers before you buy it.

I'm also going to guess that because you have an "ultrawide" type display, that the available resolutions the display is "communicating to" the iMac DO NOT match up with the potential HiDPI resolutions that the iMac can output. Thus, the iMac is picking the highest resolution it DOES think the display can handle.

If the Club3d adapter doesn't work, I'd suggest you return or sell the ACER and get a NON-ultrawide display (27" or larger) 4k display with a resolution of 3840x2160.
THAT should give you 4k in HiDPI mode @60hz with the appropriate adapter (see above).

Again, only my "best guess".

 

[Rumpot]

Thanks for your comment. Why do you think an active minidisplayport-to-HDMI 2.0 adapter would give me 60hz( I am getting 3840 x 1600 @ 30 Hz)? I thought displayport is the best connection one would want to use. I am beginning to think that the apple document is wrong and no Late 2013 iMac will push ~4k@60

 

[dpfenninger]

Thanks for your comment. Why do you think an active minidisplayport-to-HDMI 2.0 adapter would give me 60hz( I am getting 3840 x 1600 @ 30 Hz)? I thought displayport is the best connection one would want to use. I am beginning to think that the apple document is wrong and no Late 2013 iMac will push ~4k@60

Any updates to this? I am an iMac 27" Late 2013 owner as well, and had been considering a 4k monitor, but only want to pursue it if it's possible to do it at 60Hz. From my initial Googling, I have yet to find someone that has been successful with this, so I'm increasingly thinking that Apple's support doc is just incorrect...but I hope I'm wrong.

Anyone?

 

[Rumpot]

Any updates to this? I am an iMac 27" Late 2013 owner as well, and had been considering a 4k monitor, but only want to pursue it if it's possible to do it at 60Hz. From my initial Googling, I have yet to find someone that has been successful with this, so I'm increasingly thinking that Apple's support doc is just incorrect...but I hope I'm wrong.

Anyone?

Yes and no. It might work for you if your doing 4k and updating to Sierra. I can not get full resolution on my UW(3840x1600), but I have 2560 by 1440@60, and I finally gave up. This works for me as I only use the monitor for the FCPX timeline/scopes so the resolution drop is not too bothersome

 

[jloyer]

Hello
with my setup I've just reach this resolution @ 48Hz :

iMac 27 late 2013 - Nvidia 780M - Thunderbolt to hdmi 2 adapter from 3dclub (CAC 1170) - HDMI 2 cable (same brand) - Dell U3219Q monitor (HDMI input)

Using SwitchResX settings :

I don't think I can go beyond ... so that's not 4k@60Hz but that's ok for me

 

[dpfenninger]

I eventually gave up...sort of. I connected my iMac to a 4K TV at 30Hz. It's fine for the handful of times I have the need for it, as I don't plan on using it for any fast motion stuff.