DIY 5k Monitor - success :-)

[i486dx2-66]

Are there any actual changes with the new version of the R1811? My understanding of HDMI 2.1 is that vendors are free to relabel any existing 2.0 device as 2.1... so a lot of devices were "refreshed" without any actual changes being made.

Back when I did my research, about a year ago, the R1811 board was $260 + $28.54 shipping, for the version without a power supply. At that time, the T18 was just $190 + $28.54 shipping for the equivalent combo. Today, that T18 is $180 + $27.27, so it has actually gone down a touch. Not quite apples-to-apples given the missing power supply, but still, $325 is pretty steep... 🤷‍♂️

 

[PaulD-UK]

It's not obvious if there are any hardware changes to the R1811 v4 HDMI 2.1 board. Possible not?

The most obvious difference is that it has new improved firmware from Realtek (who make the main chip), which enables reduced bitrate 5K using HDMI.
It also gives 8/10-bit depth info.

This is the first board with Realtek f/w since the original 2018 Paramount labelled precursor to the R9A18 board.

 

[DSTOFEL]

I’ve got a late 2015 27 inch iMac that has that gorgeous 5k display. I’m wanting to turn this into a monitor that I can use with a Mac Studio setup as the main display.

After reading through many of the posts on this thread, it seems that the R1811 is the best solution. Is my understanding correct that I can use this board to transform my iMac into a display using this board while still retaining the full performance of the display (ie brightness, colors, etc…)?

If so, is the board in my attachment considered the best option? Or, is there another board that is the top recommendation? I don’t mind paying a bit more for the best solution. Thanks in advance! View attachment 2365455

I got the display off today and I have the LM27QQ1 part number listed on the display. I’m planning to order the HDMI 2.1 version for $325 tomorrow from StoneTaskin. Thanks everyone for the advise/support!

 

[PaulD-UK]

For a 2015 iMac your screen should be LM270QQ1 SD(C1). The last 2 characters in brackets are the significant identifier.
EDIT: 2015 iMacs have a B1 panel. C1 is 2017.

 

[DSTOFEL]

For a 2015 iMac your screen should be LM270QQ1 SD(C1). The last 2 characters in brackets are the significant identifier.

So, my display has listed as its part number: LM270QQ1 (SD) (B1). I put a screen shot. The vendor that I was planning on buy the board from (ie StoneTaskin) has 3 options listed for the R1811 5K V.4 board: LM270QQ1, LM270QQ2 and “HDMI 2.1 Latest Version”. The 3 selections are mutually exclusive and the HDMI 2.1 option doesn’t specify if it is for the LM270QQ1 or LM270QQ2 board. There is no option during the checkout process to specify that my display has as its last two characters in the part number (B1). It’s very confusing.

Has anyone else purchased from this R1811 V.4 board from this vendor? If so, I’m curious how you determined which option to choose.

 

[PaulD-UK]

You’re right. The 2015 iMac has a B1 screen. C1 is 2017.

When you make your purchase of the HDMI 2.1 board email them to tell them which screen panel you have. Or fill in their web query form.
They have very good customer service.

 

[Regulus67]

So, my display has listed as its part number: LM270QQ1 (SD) (B1). I put a screen shot.

Has anyone else purchased from this R1811 V.4 board from this vendor? If so, I’m curious how you determined which option to choose.

I have the same iMac 27" late 2015 LM270QQ1, identical panel I believe.
(SD)(B1) is not needed when making the choice.
And I also have the R1811 from StoneTaskin (with HDMI 2.0). I wanted a good one, and was less concerned about the higher price. It had everything I wanted, and I'll buy it again if I decide to build another DIY 5k display.
And the remote is quite good.
In addition, I purchased two crossover pairs for the internal speakers, that PaulD-UK posted a while back. One extra pair, in case I do another build.

And StoneTaskin gave me a fantastic support, when it turned out the cable was faulty. They shipped a replacement and gave me advice and additional information, I didn't have at first.

I have documented all of this in here

 

[DSTOFEL]

I have the same iMac 27" late 2015 LM270QQ1, identical panel I believe.
(SD)(B1) is not needed when making the choice.
And I also have the R1811 from StoneTaskin (with HDMI 2.0). I wanted a good one, and was less concerned about the higher price. It had everything I wanted, and I'll buy it again if I decide to build another DIY 5k display.
And the remote is quite good.
In addition, I purchased two crossover pairs for the internal speakers, that PaulD-UK posted a while back. One extra pair, in case I do another build.

And StoneTaskin gave me a fantastic support, when it turned out the cable was faulty. They shipped a replacement and gave me advice and additional information, I didn't have at first.

I have documented all of this in here

Awesome! Thank you so much for the information. I‘m going to look into those crossover pairs as well before making my order as I’d like to have the option to keep/use the internal speakers….even though I have a great pair of Bose speakers that I used for that iMac! Great to have options. Nice to know that I picked a quality vendor as well!

 

[xxx_BadLuckMikey_xxx]

Hey all! I am about to start my iMac conversion (Late 2015, R1811 w/HDMI 2.1) and would like to utilize as many of the stock ports as possible. Has anyone had success using the mini DisplayPort cut outs to extend HDMI?

My thought is to use a mDP female to mDP female adapter for the port, a mDP male to HDMI 2.1 cable internally to the driver board, and the same cable externally to the input device.

mDP Female to Female
mDP Male to HDMI 2.1 Male

Is this even functionally possible with the DP and HDMI protocols?
If anyone has any suggestions on how else to use the existing iMac I/O ports, or has maintained “stock look”, I’d love feedback or photos!

 

[DSTOFEL]

You’re right. The 2015 iMac has a B1 screen. C1 is 2017.

When you make your purchase of the HDMI 2.1 board email them to tell them which screen panel you have. Or fill in their web query form.
They have very good customer service.

Thanks for the info!. Greatly appreciated!

 

[Aiwi]

Hey all! I am about to start my iMac conversion (Late 2015, R1811 w/HDMI 2.1) and would like to utilize as many of the stock ports as possible. Has anyone had success using the mini DisplayPort cut outs to extend HDMI?

My thought is to use a mDP female to mDP female adapter for the port, a mDP male to HDMI 2.1 cable internally to the driver board, and the same cable externally to the input device.

mDP Female to Female
mDP Male to HDMI 2.1 Male

Is this even functionally possible with the DP and HDMI protocols?
If anyone has any suggestions on how else to use the existing iMac I/O ports, or has maintained “stock look”, I’d love feedback or photos!

Nice idea! I haven’t tried it as the card already has three dp inputs (usb-c, 2x dp). I tried converting it to a mini hdmi though, but using the adapters I had I was only able to get 4k60.

This was my take on a stock looking iMac: https://github.com/aiwipro/5K-iMac-Studio-Display-Stock-Look

 

[PaulD-UK]

Quote: “My thought is to use a mDP female to mDP female adapter for the port, a mDP male to HDMI 2.1 cable internally to the driver board, and the same cable externally to the input device.”

Possible problems:
MiniDP had its heyday 2009-2015. That was the era of DP 1.2, which doesn’t do 5K. It’s unlikely that adapters etc will support 5K.

HDMI<>DP requires active powered converters. Any converter you use will require an external power supply.
This conversion is not-neccessarily bi-directional, so you have the use the right converter at each end of the cables.

 

[gaule]

hello everyone,

Excited to build 5K iMac late 2015 build with R1811 w/HDMI 2.1. I am based on Europe (France). Where did you buy R1811, Aliexpress or direct stonetaskin.com official site? Did you pay any duty or import tax on arrival? I am planning to switch between macMini M2, MacBook Pro M1 Pro (don't need PD) and PC with RTX 3080. I will appreciate if anyone can give an idea to switch between 3 inputs ? thanks

 

[PaulD-UK]

Most AliEx vendors still seem only to have the HDMI 2.0 version.
Getting it direct from ST seems the easiest/quickest/safest.
No tax, but that is country specific. YMMV...

The Sabrent KVM switchs have been mentioned in this forum as working, but they only seem to have 2 computer versions.

 

[gaule]

Most AliEx vendors still seem only to have the HDMI 2.0 version.
Getting it direct from ST seems the easiest/quickest/safest.
No tax, but that is country specific. YMMV...

The Sabrent KVM switchs have been mentioned in this forum as working, but they only seem to have 2 computer versions.

thanks mate for the quick reply. I will order directly from them. I will see with Sabrent KVM switch once I'm done with the setup.

 

[PaulD-UK]

Or you could have a 3 computers connected permanently - using USB-C and both DP inputs with USB-C>DP 8K cables and make the choice with the R1811 input selection.

 

[gaule]

Or you could have a 3 computers connected permanently - using USB-C and both DP inputs with USB-C>DP 8K cables and make the choice with the R1811 input selection.

Yes, not a bad idea. My concern is that when I connect to all three inputs and lets say I chose macMini what happens to other input devices, will they sleep or stay active as they are connected to monitor?

 

[gaule]

After a quick search, I think this switch will fulfill my requirements.

 

[PaulD-UK]

The problem with HDMI output with M1 Pro and M2 mini Macs is that they only support 4K/60 from their HDMI socket.
The problem with the R1811 board is that even with the HDMI 2.1 option the HDMI input only operates at a reduced bit-rate compared to the DP and USB-C inputs, so the HDMI input displays 5K at YUV 4.2.0 not RGB.
This is not so much a problem for video, but colour still images on the screen don't look as good as RGB.

 

[gaule]

@PaulD-UK , you are right. Thanks for the clarification. As you suggest, here is my plan to connect all inputs:

1. controller DisplayPort 1.4 to macMini using Thunderbolt 4 to DisplayPort (8K@60Hz) cable
2. controller DisplayPort 1.4 to MacBook Pro via Thunderbolt 4 to DisplayPort (8K@60Hz) cable
3. controller Type-C to PC via DisplayPort 1.4 to Thunderbolt 4 cable

do you think I will get the best result possible from the board and the panel?

 

[DSTOFEL]

The problem with HDMI output with M1 Pro and M2 mini Macs is that they only support 4K/60 from their HDMI socket.
The problem with the R1811 board is that even with the HDMI 2.1 option the HDMI input only operates at a reduced bit-rate compared to the DP and USB-C inputs, so the HDMI input displays 5K at YUV 4.2.0 not RGB.
This is not so much a problem for video, but colour still images on the screen don't look as good as RGB.

I’ve got the R1811 V4 (HDMI 2.1) option coming in next week from StoneTaskin. I’m planning to put it in my late 2015 27 inch 5K iMac and most likely connect it to a M2 Mac Studio to use as the main display (ie primarily for photo and video processing).

If I’m understanding your post correctly, even though the M2 Mac Studio (in my case) supports 5K/60 Hz via HDMI…..the R1811 controller board’s HDMI 2.1 port operates at a reduced bit rate at 5K/60Hz.

So, in order to get the full 5K performance out of this display I’d need to connect it to the Mac Studio via:

Controller’s DisplayPort 1.4 to Mac Studio via TB4 to Display Port cable.

Is my understanding correct?

 

[gaule]

I ordered yesterday but got the email this morning saying that shipment will be delayed till end of this month because driver board is still in production. As @PaulD-UK indicated, controller's HDMI 2.1 still has some limitation compared to DP1.4. So I am thinking to order R1811 V.4 LM270QQ1 without HDMI 2.1 in order to save some time and money as I am not going to use HDMI anyway. What do you think guys ?

​

 

[PaulD-UK]

Quote: @gaule
"my plan to connect all inputs:
1. controller DisplayPort 1.4 to macMini using Thunderbolt 4 to DisplayPort (8K@60Hz) cable
2. controller DisplayPort 1.4 to MacBook Pro via Thunderbolt 4 to DisplayPort (8K@60Hz) cable
3. controller Type-C to PC via DisplayPort 1.4 to Thunderbolt 4 cable"

That would work fine.
If you connect the PC to the USB-C port on the R1811 you would need a bi-directional cable - not all cables work both ways.
You could connect the PC with a DP 1.4<>DP 1.4 cable, and connect the Mac mini with a video-capable USC-C/TB3 or 4 cable.
There are no recent reports of problems or damage of the Mac's USB-C port by connecting this way.

Quote: "I am thinking to order R1811 V.4 LM270QQ1 without HDMI 2.1..."
I don't think there is any real difference in the performance of the USB-C or DP inputs.
The only noticeable difference is in the firmware - the HDMI 2.1 version shows more information in the OSD display.

Quote: @DSTOFEL "...in order to get the full 5K performance out of this display I’d need to connect it to the Mac Studio via: Controller’s DisplayPort 1.4 to Mac Studio via TB4 to Display Port cable."

Yes.

 

[gaule]

@PaulD-UK Thanks for the precision. I would prefer bi-directional cable for PC rather than connecting to mac devices to be on safe-side.

 

[PaulD-UK]

At this time the only real information we have about the new R1811 HDMI 2.1 version is the @Aiwi blog:

GitHub - aiwipro/5K-iMac-Studio-Display-Stock-Look: Converting a 5K iMac to act as a generic 5K display is nothing new. What is yet to be found is a conversion that keeps the stock iMac look. This is what this project aims to achieve.

Converting a 5K iMac to act as a generic 5K display is nothing new. What is yet to be found is a conversion that keeps the stock iMac look. This is what this project aims to achieve. - aiwipro/5K-i...

github.com

He ends with the warning:

"Final Note​

Using a USB-C cable from a Macbook works great on both inputs. Using an, allegedly bi-directional, USB-C to DP cable with an RTX3080 DP to USB-C (iMac Display) does not work on either input. I might purchase another USB-C DP cable to investigate further."

This may be caused by the extra USB-C 90º/straight adapters that @Aiwi uses in his input cables?
@joevt has tested 90º adapters with Thunderbolt 3. Five adapters worked, six failed in his test.