DIY 5k Monitor - success :-)

[Edge]

After a brief moment of panic this morning, I have just connected my JRY board using a 12V supply.

Initially I saw what looked like a panel test, changing between solid colours (red, green, etc.)

Then I was only seeing No Display and Entering Power Saving Mode despite trying a USB-C cable (unsure if UDB-PD charging only or if capapble of driving a 5K display) and an old HDMI cable.

But now to my surprise I am seeing what appears to me to be 5k@30Hz via HDMI on my Macbook Pro M1 Pro.

JRY (no fan):
USB-C + charging: 5k 8 bit
1x DP 1.4: 5k 8bit
1x HDMI 2.0: 4k 60Hz

Displays Preferences shows 2560x1440 Default scaled image size.

The About This Mac Displays tab shows 26.5 inch (5120x2880).

System Report Graphics/Displays shows;

HDMI:
Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 30.00Hz
Mirror: Off
Online: Yes
Rotation: Supported

I wonder if this is expected? (Edit: Yes, it appears my display is behaving as expected)

SwitchResX can give an indication of the timing and output resolution (but the timing for dual link SST modes is faked by Apple).

AGDCDiagnose can get link rate/link width for a DisplayPort display, but it doesn't give that info for devices in an MST topology except for the first device. AGDCDiagnose may give pixel info and timing info for modern AMD GPUs but not Intel GPUs. There might be some info in the GTRACEDATASTREAM but you need to decode it - I should add that to AllRez.

AllRez should give all the info for all the GPUs (but not all the info for M1 GPUs). Legacy GPUs for Intel Macs require a kext to get pixel output info (and the kext will allow setting pixel output info such as 6,8,10 bpc, RGB or 4:2:2). I haven't updated the GitHub with the latest features yet.

Am investigating which of these tools will give me an accurate summary.

Edit: SwitchResX confirms HDMI is running in 2560x1440@30Hz HiDPI mode, and shows the highest resolution available 3840x2160@60Hz which is expected via HDMI. Also found a USB-C cable which supports alt-mode displays and screen is now running at 5K@60Hz via USB-C to USB-C cable.

On-screen menus have been changed to English from Chinese, via the second last menu item, then the first option which allows to to select your chosen language (incl. English/Russian/French/Spanish and three Asian language options).

The JRY driver board does not appear to facilitate automatic input sensing — you have to select Thunderbolt, DP or HDMI — but I will investigate further.

 

[Rembihnutur]

I did not take any pictures while cutting the part, so bear with me:

- I cut away the four tabs to the left and right. This makes the new module fit along the x- and y- axis.
- I filed down the flat area until i reached the original circular surface on which the original camera rests. This gives enough room in the z-axis.

I've marked the surface which was ground down with pink on the attached picture.

Hey

Thank you. It worked very good to fit the Camera inside the case. Unfortunately I can't really use it now.
I tried it multiple times outside of the iMac and it worked perfectly. I was able to control stuff like saturation with CameraController https://github.com/Itaybre/CameraController
I tested the camera on multiple steps inside the iMac and right before I glued the Display in the case. the Display lay flat in the case and on the camera, everything worked perfectly.
Then I glued it in and now the autofocus does not work. It's completely blurry. And when I try to use CameraController the Camera freezes when I adjust settings and I have to unplug my MacBook to see a camera image again.

I don't know if I want to open the iMac again, and im not sure what I could do to fix it.

 

[Semmo]

T19 (no fan):
no USB-C
2x HDMI 2.1 5k 10 bit (DSC)
2x DP 1.4: 5k 10 Bit (DSC)

Is it confirmed on Mac (M1 Max in my case) that the T19 (2.1 HDMI Ver) is DSC 10Bit with DP1.4 Single Cable?

I reached out to the seller but it isn't clear in the answers provided. seems the real answer is just 5K on Mac?..

Hi please confirm


T19 (no fan): no USB-C 2x HDMI 2.1 5k 10 bit (DSC) 2x DP 1.4: 5k 10 Bit (DSC)
Read


MacBook Pro 14" M1 Max DSC 5k 10Bit?
Read


2.1didn’t. test


do 1.4. tested. 5K. 10 bit


USB-C to DP1.4?
Read


we. use. windows. to. tested. 5K. ok


can you test Mac?

 

[Aiwi]

Hey

Thank you. It worked very good to fit the Camera inside the case. Unfortunately I can't really use it now.
I tried it multiple times outside of the iMac and it worked perfectly. I was able to control stuff like saturation with CameraController https://github.com/Itaybre/CameraController
I tested the camera on multiple steps inside the iMac and right before I glued the Display in the case. the Display lay flat in the case and on the camera, everything worked perfectly.
Then I glued it in and now the autofocus does not work. It's completely blurry. And when I try to use CameraController the Camera freezes when I adjust settings and I have to unplug my MacBook to see a camera image again.

I don't know if I want to open the iMac again, and im not sure what I could do to fix it.

That's really unfortunate! I don't really have any tricks for you except "buy more adhesive strips and try again...". Possibly it might be too tight up there and the camera is unable to move. But that's really just a guess.

On completely unrelated note note, I went the path of using the onboard amp on the R1811 with two crossovers for the original speakers. It works really well.

What tipped the scale was that I need to have Monitor Control installed in order to have brightness controls. With that great software, I get the ability to change displayport volume included.

 

[PaulD-UK]

Quote: "Is it confirmed on Mac that the T19 (2.1 HDMI Ver) is DSC 10Bit with DP1.4 Single Cable?"

The vendor's sales video confirms 10-bit with a single DP 1.4 cable from a Windows computer.
If they don't have a Mac that is as far as they can tell you.

No one has posted to this thread about a build with a T19 - if you have please post here.

But: Many people have had good results from the T18 using a Mac, and that is apparently similar in a lot of respects.

The T18 and the T19 use the same Realtek RTD2718Q-CG video driver chip, which is a DP 1.2 chip - the same chip as the R9A18 and JRY boards.

Indeed, IF the R1811 uses the same chip as the LG 5K Ultrafine - the RTD2799 - which is certainly possible?, (anyone who knows please confirm )
then that too is a dual-lane DP 1.2 chip, BUT Realtek have produced a companion chip, RTD2185, which is reported from a press release (in Chinese):
"That is to say, Realtek issued a press release saying that its RTD2185 DP1.4 MST (single input) converter can transfer two DP1.2 to its own dual RTD2799 DP1.2 fusion screen driver, thus supporting one incoming (DP 1.4) line to support 5K 60hz"

RTD2185 DP1.4 MST presumably means that Alt-mode DP tunnelling over TB or USB-C can carry single cable two streams (like Apple do for a the 6K Pro XDR display, and LG on the original 5K Ultrfine) and on a PC, this allows MST daisy-chaining of displays under Windows/Linux.

It seems likely that to get single cable DP 1.4 5K/60 input, then Hajing Cool must be using a chip like the RTD2185 to convert 1 x DP.1.4 to 2 x DP 1.2 to input to the RTD2718Q-CG.
Which presumably they do to the T19.

In short, neither the T18 or the T19 are described by the vendor as Mac-compatible, but as the T18 most certainly is, then why wouldn't the T19 also be?

Please report here if you take this further.

Ha ha 'daisy-chaining' comes over as 'chrysanthemum-chaining' from the Chinese when using Apple's Translate.

 

[Semmo]

Thanks Paul. Yeah I’m on the fence whether to get the T19. My needs are as follows which makes me not justify the 1811

5k 10bit DSC Full Colour
Able to use orig speakers.

That’s it. Not interested in PD or any other option.

I know the 1811 is the go to for reputation. But spending that much makes me second doubt.

Maybe I will wait for the next chip version. As I only want to do this once.

Currently using the 27 2015 with the built in screen control. Obviously can’t cut paste of move windows. Buts it’s very useful non the less using just one keyboard and trackpad automatically

 

[vakman]

The panel (any year) + R1811 can only do 5K over a single cable with a DP 1.4 graphics card in the Mac.
Apple only moved from DP 1.2 to DP 1.4 in 2018 (iMac 2019).
And to get 5K RGB instead of YUV the graphics card has to support DSC, which came even later.

Or using the high wattage USB-C port using a Thunderbolt 4 cable on both ends. Works better than the DP1.4 as I’m finding and delivers Rock Solid 5k with one discrete cable

 

[PaulD-UK]

Quote: @Semmo
"I know the 1811 is the go to for reputation. But spending that much makes me second doubt.
Maybe I will wait for the next chip version. As I only want to do this once."

Hmm. I can't see any 'next chip version' coming any time soon.
The DP 1.2 RTD2718 and the RTD2799? chips, which are what I guess all the current boards are utilising, were developed nearly a decade ago, and received a firmware? update to support DP 1.4 in various ways in.2018/19.

They were developed for monitor manufacturers to produce 4K/>60 products, by Iiyama, Viewsonic, AOC and LG for 5K.

5K for the future in 2016 may have seen like a sure bet, but that hasn't happened - except for Apple products.
So I don't see any demand for 'new chip versions' and I don't think they will be developed.

They only appeared on retail LCD driver for amateur use when the demand came for testing and reusing of 2nd user LCD panels.
And as the need for more and more old iMac 5K Macs to be given a new life as a monitor, the demand is not diminishing.

But the only improvements will be in driver software/firmware, like the new version of the R1811 that supports the use of single cable 5K HDMI v2.1 (seemingly at Reduced Bit Rate YUV).
The older version only did 4K with HDMI 2.0. These old variants may eventually become more affordable.
But not yet, I think, as the new version isn't yet widely available AFAIK.

All this speculation is AFAIK...
('Chrysanthemum-chaining' from the Chinese using Apple's Translate)

 

[USB3foriMac]

I should have added in my original post that I had just found this marvellous circuit board.

PD Buddy Sink

USB Power Delivery is a cool standard for getting lots of power—up to 100 W—from a USB Type-C port. Being an open standard for supplying enough power to charge phones, laptops, and just about anything else under the sun, USB PD is poised to greatly reduce the amount of e-waste produced worldwide...

hackaday.io

It takes USB-PD input and can be manually programmed to output one of a range of outputs. The project creator believes it is fully compliant with the USB-PD spec.

You can find easier to use circuit boards with dip switches and even display on AliExpress and similar platforms. They are known under the term "type C decoy".

 

[Patrick874]

I think you may only get 4K from a 2017 Intel Mac over a single cable, and in HiDPI Retina mode that will display at 1920x1080.

But the R1811 should show the full 4K resolution as the output parameters.
And so should System Settings>General>About-Displays (in Ventura, presumably in the equivalent About This Mac in Monterey).
So I don't know what's going on. Sorry.

EDIT: Since your iMac is only DP 1.2, maybe setting the R1811 to DP 1.2 instead of 1.4 would make a difference?

I connected a test PC with an Nvidia RTX 2080 to the monitor. It is output to the monitor via Displayport 5k@60Hz.
No matter whether I select DP1.2 or 1.4 in the monitor menu, I get a 5k image with just one DP cable.
The only problem is the 2017 iMac. I still have a Thunderbolt to two DisplayPort adapter, but no double DP menu in the monitor menu. I think I need a firmware update

 

[konbrecht]

Does anyone have a photo of the chip in R1811? Is the RTD2799 really there?

 

[PaulD-UK]

@Patrick874 Yes, I've found out DP 1.2 supports 5K/60 with the R1811, running 4 lanes of HBR2 with DSC.
USB-C 3.x cables are only 2 lane I think, so it has to be a TB3/4 cable to get 4 lanes - if not using a DP<>DP cable.

Do you get full RGB colour, or YUV (YCbCr) with your PC? The OSD Color page will tell you.

Yes, you need to revert to DP 1.2 firmware to get two cable operation.
If you find you have any problem with your TB3>2xDP adapter, you should be able to connect to the R1811 (with 2xDP 1.2 firmware) directly to your iMac if you have two USB-C>DP 4K cables - each cable only carries half the screen data.

But I'm a bit mystified why you don't get full 4K/60 over a TB3 cable ???
The 2017 27" iMac's specs says it supports that (if the cable is 4 lane maybe). I guess it's the lack of DSC?

 

[PaulD-UK]

"Does anyone have a photo of the chip in R1811? Is the RTD2799 really there?"

Nobody who has had the heatsink off to look has posted here.
It could be, or it could be a different (similar) chip...

All the data sheets are 'Restricted. Commercial Partners Only':
All I can find is for the RTD2799:
'A total of 4 HDMI + 2 DP inputs, 8Lane eDP (HBR2) output (resolution up to 5120x2880@60Hz)
can support dual HDMI 2.0 input or dual DP 1.2 input mode in DP and HDMI mode.
Built-in 8051 MCU to 12-bit colour depth.
Built-in DDR3 controller, supporting up to two 16-bit DDR3 RAM.'

But the PCB trace layout of the R1811 is very similar to the board in the LG 5K Ultrafine, though that has an Intel TB chip and the R1811 has DP-in sockets, both 8 lanes for 2 sockets/channels.
The the LG works with 2 DP 1.2 over TB channels to get 5K.

Whatever is in the new R1811 with the HDMI 2.1 upgrade, it's got REALTEK branded software, (you can see this in the blog posted on GitHub by @Aiwi).
I think that means it's still getting active development from REALTEK. Like maybe the LG 5K Ultrafine's chip has over the years.

 

[joevt]

@Patrick874 Yes, I've found out DP 1.2 supports 5K/60 with the R1811, running 4 lanes of HBR2 with DSC.

DisplayPort 1.2 doesn't support DSC. What you're using is DisplayPort 1.4 with HBR2 link rate.
It's interesting that the monitor when set to DP1.2 still accepts DSC. Perhaps the switch is only reducing the link rate and not disabling other DisplayPort 1.4 features.
You can use AllRez on an Intel Mac to gather the DPCD info from the display. Gather the info for all ports and all modes.

USB-C 3.x cables are only 2 lane I think, so it has to be a TB3/4 cable to get 4 lanes - if not using a DP<>DP cable.

USB-C cables have 4 SuperSpeed lines. A USB-C dock or display can choose to use 2 lines for DisplayPort and 2 lines for USB 3.x (transmit and receive), or 4 lanes for DisplayPort and no USB 3.x. In either case, USB 2.0 is supported using a separate HighSpeed differential pair. A USB-C dock or display might have a switch disable USB 3.x to allow 4 lanes of DisplayPort. Some USB docks only support USB 2.0 so that the DisplayPort can use all 4 lanes.

Do you get full RGB colour, or YUV (YCbCr) with your PC? The OSD Color page will tell you.

Yes, you need to revert to DP 1.2 firmware to get two cable operation.
If you find you have any problem with your TB3>2xDP adapter, you should be able to connect to the R1811 (with 2xDP 1.2 firmware) directly to your iMac if you have two USB-C>DP 4K cables - each cable only carries half the screen data.

But I'm a bit mystified why you don't get full 4K/60 over a TB3 cable ???
The 2017 27" iMac's specs says it supports that (if the cable is 4 lane maybe). I guess it's the lack of DSC?

You can use AllRez to examine the connection(s) between the GPU and the display. It might list supported color modes depending on the GPU.

 

[Pondering]

Here's the chip on the r1811 v4.

 

[Aiwi]

@Patrick874 Yes, I've found out DP 1.2 supports 5K/60 with the R1811, running 4 lanes of HBR2 with DSC.
USB-C 3.x cables are only 2 lane I think, so it has to be a TB3/4 cable to get 4 lanes - if not using a DP<>DP cable.

Do you get full RGB colour, or YUV (YCbCr) with your PC? The OSD Color page will tell you.

Yes, you need to revert to DP 1.2 firmware to get two cable operation.
If you find you have any problem with your TB3>2xDP adapter, you should be able to connect to the R1811 (with 2xDP 1.2 firmware) directly to your iMac if you have two USB-C>DP 4K cables - each cable only carries half the screen data.

But I'm a bit mystified why you don't get full 4K/60 over a TB3 cable ???
The 2017 27" iMac's specs says it supports that (if the cable is 4 lane maybe). I guess it's the lack of DSC?

As per this guide, the following is true:

For completeness’ sake, I’ve added DisplayPort 1.4 (without DSC, limited to 5k 8bit) information below:

Vendor	Architecture	Series
AMD	Polaris/Vega	RX 4xx/5xx/56/64 series

• Intel Kaby and Coffee Lake support DisplayPort 1.4 however only for internal displays with eDP, external displays are limited to DisplayPort 1.2

Additionally, while Polaris and Vega GPUs support DisplayPort 1.4, all 2017 and older Macs do not due to the Thunderbolt Controller present. Titan Ridge released with the 2018 Coffee Lake series Macs is the first to support DisplayPort 1.4 via external displays.

 

[Edge]

You can find easier to use circuit boards with dip switches and even display on AliExpress and similar platforms. They are known under the term "type C decoy".

I will have a look, thanks for the specific search term.

Coincidentally, I just came across this adapter

DC Adapter Type C Female to Male 100W 90 Degree Angled Fast Charge 5.5 x 1.7 mm/5.5 x 2.1 mm/5.5 x 2.5 mm DC Socket Socket for USB Charger Type C (5.5 * 2.1mm)

DC Adapter Type C Female to Male 100W 90 Degree Angled Quick Charge 5.5x1.7mm/5.5x2.1mm/5.5x2.5mm DC Hollow Socket for USB Charger Type C Special feature: 1. PD FLASH CHARGING Fast full charging, easier office work, TYPE C female to DC male, PD fast charge is widely compatible, deception chip, du...

www.amazon.com.au

 

[PaulD-UK]

Quote: @Pondering "Here's the chip on the r1811 v4. {RTD2718Q}"

'Speak Friend and enter'! Open Sesame!

@i486dx2-66 in post 515 has already confirmed that it's the RTD2718Q in the Hajing Cool T18 (and R9A18).
Google immediately shows that what is sold as the Hajing Cool T19 uses this as well, where it comes up called the Dauking DK-8EDP and made by a manufacturer in Shenzhen.

The Dell 4K G3223Q, a curved gaming monitor, uses it - as well as dozens of other manufacturer's monitors that may use the 2718 or 2718Q chips.

However most of the many references to the RTD2718/RTD2718Q describe it as an HDMI 2.0 chip.

Only the T19/DK-8EDP, and now the R1811 v4 HDMI 2.1 version, are sold as able to do HDMI 2.1.

The LG 5K Ultrafine's RTD2799 is a similar chip in most ways, but apparently only manages 4K (or 5K/39) using a USB-C cable.
So the RTD2718Q has been developed to be more versatile.

So it seems you make your DIY board choice between versions of the same thing.
I think the JRY-W9CUHD-AA1 and R9A18 V1 boards may use the RTD2818 chip.
But the R9A18 V1.1 board being sold now has the RTD2718Q chip, as do all the others sold at this moment.

 

[PaulD-UK]

Quote: @joevt "DisplayPort 1.2 doesn't support DSC. What you're using is DisplayPort 1.4 with HBR2 link rate."

Thanks for setting me right.
I think that all these Video Driver chips that started to be produced about the time of DP 1.3 just refer to the DP version as a speed indicator.

The new R1811 board, with HDMI 2.1 enabled, shows more information on the start-up screen and in the OSD.

With DP/USB-C input:
DO: DP
5120x2880at60.0Hz
H: 175.5KHz PCLK: 926.6MHz
HDCP 2.2 Sink
SDR
DSC On
OD On

With HDMI 2.0 input:
D3: HDMI
3840x2160at60.OHz
H: 135.OKHz PCLK: 594.0MHZ
HDCP 2.2 Sink
SDR
DSC Off
OD On

I haven't got the HDMI 2.1 splash screen info. Maybe @Aiwi has it?

The OSD 'Factory Settings' shows:
With DP input:
DisplayPort Debug Message
4 Lane HBR2 RGB 10 Full

With HDMI 2.1 input:
4 Lane RBR УСЬС+422 10 Full

With HDMI 2.0 input:
4 Lane RBR УСЬСт422 8 Full

 

[Patrick874]

@Patrick874 Yes, I've found out DP 1.2 supports 5K/60 with the R1811, running 4 lanes of HBR2 with DSC.
USB-C 3.x cables are only 2 lane I think, so it has to be a TB3/4 cable to get 4 lanes - if not using a DP<>DP cable.

Do you get full RGB colour, or YUV (YCbCr) with your PC? The OSD Color page will tell you.

Yes, you need to revert to DP 1.2 firmware to get two cable operation.
If you find you have any problem with your TB3>2xDP adapter, you should be able to connect to the R1811 (with 2xDP 1.2 firmware) directly to your iMac if you have two USB-C>DP 4K cables - each cable only carries half the screen data.

But I'm a bit mystified why you don't get full 4K/60 over a TB3 cable ???
The 2017 27" iMac's specs says it supports that (if the cable is 4 lane maybe). I guess it's the lack of DSC?

What I now know is: my iMac 2017 has Thunderbolt 3,
but the built-in AMD Radeon RX580 graphics card can only do DP1.2
I'm now looking for a firmware update for double DP.
Does anyone have instructions on how to flash this? and what tools and firmware do I need?
should I buy from Stone Taskin?

DIY 5K universal R1811 V.4 Driver Board USB-C Freesync EDP DP1.4 Comp

For creating a good consumer experience, please confirm your LCD/LED Screen part number before ordering. If you're a wholesale/distributor in your country please contact us for a better price and the best logistic options...

stonetaskin.com

 

[USB3foriMac]

I will have a look, thanks for the specific search term.

Coincidentally, I just came across this adapter

DC Adapter Type C Female to Male 100W 90 Degree Angled Fast Charge 5.5 x 1.7 mm/5.5 x 2.1 mm/5.5 x 2.5 mm DC Socket Socket for USB Charger Type C (5.5 * 2.1mm)

DC Adapter Type C Female to Male 100W 90 Degree Angled Quick Charge 5.5x1.7mm/5.5x2.1mm/5.5x2.5mm DC Hollow Socket for USB Charger Type C Special feature: 1. PD FLASH CHARGING Fast full charging, easier office work, TYPE C female to DC male, PD fast charge is widely compatible, deception chip, du...

www.amazon.com.au

Yes, this contains the same "decoy" circuit, fixed at the selected voltage. I have one of these, too. Works the same, but I prefer one where I can adjust the output voltage via dip switches. Makes them more universal and reusable.

 

[Aiwi]

Quote: @joevt "DisplayPort 1.2 doesn't support DSC. What you're using is DisplayPort 1.4 with HBR2 link rate."

Thanks for setting me right.
I think that all these Video Driver chips that started to be produced about the time of DP 1.3 just refer to the DP version as a speed indicator.

The new R1811 board, with HDMI 2.1 enabled, shows more information on the start-up screen and in the OSD.

With DP/USB-C input:
DO: DP
5120x2880at60.0Hz
H: 175.5KHz PCLK: 926.6MHz
HDCP 2.2 Sink
SDR
DSC On
OD On

With HDMI 2.0 input:
D3: HDMI
3840x2160at60.OHz
H: 135.OKHz PCLK: 594.0MHZ
HDCP 2.2 Sink
SDR
DSC Off
OD On

I haven't got the HDMI 2.1 splash screen info. Maybe @Aiwi has it?

The OSD 'Factory Settings' shows:
With DP input:
DisplayPort Debug Message
4 Lane HBR2 RGB 10 Full

With HDMI 2.1 input:
4 Lane RBR УСЬС+422 10 Full

With HDMI 2.0 input:
4 Lane RBR УСЬСт422 8 Full

View attachment 2355739
View attachment 2355740
View attachment 2355741
View attachment 2355742
View attachment 2355743

This is the R1811 HDMI 2.1 splash screen:

 

[Izzie24]

I've noticed gradient borders on my iMac's late 2015 screen, which seems to be related to the panel with the R1811 card. This issue is specifically around the edges of the screen. Has anyone encountered a similar problem or have any suggestions on how to address this? Any help or troubleshooting advice would be greatly appreciated.

 

[USB3foriMac]

I've noticed gradient borders on my iMac's late 2015 screen, which seems to be related to the panel with the R1811 card. This issue is specifically around the edges of the screen. Has anyone encountered a similar problem or have any suggestions on how to address this? Any help or troubleshooting advice would be greatly appreciated.

It's a well known degradation of the screen, unrelated to the modification described in this thread. I think it's mostly called "pink border". You should be able to find complaints easily, but there is no solution.

 

[Izzie24]

It's a well known degradation of the screen, unrelated to the modification described in this thread. I think it's mostly called "pink border". You should be able to find complaints easily, but there is no solution.

I appreciate your quick reply and insight, but I'd like to note that the 'pink border' issue was not present when the iMac was in its original configuration. This leads me to believe that the problem is not due to the screen's age or a general degradation but may be related to the R1811 card or how it interfaces with the panel in this DIY setup. Has anyone managed to mitigate this issue in a similar project?