Studio Display with Mac Pro 2013?

[arw]

Ill try and find a cable.

My point stands, the image quality is the same between the two.

Because in your scenario it is. Your MBP is not sending a 5K signal but the same sub-optimal 4K signal as the MP6,1.
But the MBP is capable to output 5K via one (5K@60 rated) cable and once you get that to work, you should definitely see a difference.

 

[IsaacFOK]

Ok so I managed to sort the issue, if I flip the cable ends on the Apple TB4 braided cable I have 5k now.

I have to concede, yes the difference is noticeable. To think all this time I thought it couldn't get better!

 

[IsaacFOK]

It looks like it was running at half link speed.

 

[joevt]

With 20 Gbps connection (Thunderbolt 2 or USB-C cable), you get a single DisplayPort 1.2 signal which can give 4K60. The LG UltraFine 5K can accept a custom timing of 5K39, except the older Radeon GPUs like in the 2013 Mac Pro or the 2015 Mac Book Pro don't support width > 4096 properly. I don't remember if Windows supported width > 4096 with those GPUs.

 

[IsaacFOK]

Thats unfortunate, I would have been ok with 39 frames as it's not for gaming.

 

[Amethyst1]

Thats unfortunate, I would have been ok with 39 frames as it's not for gaming.

You could try making the MP run the monitor at 4096×2304 rather than 3840×2160. It might look a tiny bit better then since that's closer to the native resolution. Add a custom 4096×2304 60Hz CVT-RB v2 timing in SwitchResX, check if it works, if so, set the "Scaled resolution base" to 4096×2304. (I presume this issue is what causes the MP to use 3840×2160 instead).

 

[joevt]

You could try making the MP run the monitor at 4096×2304 rather than 3840×2160. It might look a tiny bit better then since that's closer to the native resolution. Add a custom 4096×2304 60Hz CVT-RB v2 timing in SwitchResX, check if it works, if so, set the "Scaled resolution base" to 4096×2304. (I presume this issue is what causes the MP to use 3840×2160 instead).

LG UltraFine 5K 27MD5KA 5b11 has 4096x2304 and 3840x2160 in the EDID.

LG UltraFine 5K 27MD5KL 5b74 doesn't have 4096x2304. I guess they wanted the default timing for single DisplayPort connection to support 10bpc. A custom timing for 4096x2304 might work on the MP.

Here's the timing info from 27MD5KA. It doesn't match CVT-RB2.

    DTD:  4096x2304   59.999273 Hz  16:9    142.198 kHz    593.820000 MHz (aspect 16:9, no 3D stereo)
               Hfront    8 Hsync  32 Hback   40 Hpol P
               Vfront    1 Vsync   8 Vback   57 Vpol N

 

[IsaacFOK]

You could try making the MP run the monitor at 4096×2304 rather than 3840×2160. It might look a tiny bit better then since that's closer to the native resolution. Add a custom 4096×2304 60Hz CVT-RB v2 timing in SwitchResX, check if it works, if so, set the "Scaled resolution base" to 4096×2304. (I presume this issue is what causes the MP to use 3840×2160 instead).

So I need to change the values in the third block down like this? What happens then? The SwitchResX guide is basically non existent.

 

[joevt]

So I need to change the values in the third block down like this? What happens then? The SwitchResX guide is basically non existent.

If the Current Resolutions list doesn't have a non-scaled 4096x2304 mode, then you need to create one in the Custom Resolutions list. Then click Activate Immediately or turn off and on the display (if it has a power switch) or disconnect and reconnect the display.

 

[IsaacFOK]

The current list has that size, I can activate it and the display resolution changes, seems to work ok. But it's no HiDPI which makes the UI too small.

 

[Amethyst1]

The current list has that size, I can activate it and the display resolution changes, seems to work ok.

Check that the “Scaled” checkbox next to the mode in SwitchResX is not checked. If it is checked, that’s just a scaled mode. You need an actual 4096×2304 mode.

Spoiler

If there is none, click “+” on the “Custom Resolutions” tab, select “Custom” and disable “Use simplified settings”. Enter the numbers from your first screenshot in post #97 (minus the “Scale to” row), click “OK”, save (Command-S) and click “Activate immediately”. Find the new mode in the “Available Resolutions” tab and test if it works. If so, see the next paragraph.

What happens then?

If an actual 4096×2304 mode is present and the “Scaled resolution base” set to it, all HiDPI modes will use it instead of 3840×2160 after a reboot.

 

[IsaacFOK]

Thank you, looks like it won't work, I can't activate the custom res.

Maybe my settings are wrong?

 

[Amethyst1]

Sometimes it helps to reboot and/or (re) start the SwitchResX daemon (on the “About SwitchResX” tab IIRC) to get SwitchResX to activate a mode. I have to do that quite often on my systems.

If that doesn’t work, the pixel clock may be too high. Try creating a new mode but select “Use simplified settings” and “CVT-RB v2” this time. Enter 4096 pixels, 2304 lines and 59 Hz vertical scan rate. Can you activate that mode? If you can, test it by selecting it on the “Current Resolutions” tab. If you can’t, reduce the vertical scan rate to 58 Hz and retry. If it still doesn’t work, try 57, 56, etc. until it works. You can have two custom modes in the unregistered version of SwitchResX which speeds up testing a bit.

 

[IsaacFOK]

You were right, it was the Pixel clock that was too high.

If I set it to 58Hz it's fine and now is working as all other resolutions have taken the 4096x2304 as their base now.

Do I need to have SwitchRes X Deamon running all the time now? I have paid for version so made the custom mode testing a lot faster as you say (I had to reboot for them to activate).

 

[Amethyst1]

Do I need to have SwitchRes X Deamon running all the time now?

No.

 

[IsaacFOK]

Thank you, appreciate the help!!!! Owe you a beer.

 

[Amethyst1]

If I set it to 58Hz it's fine and now is working as all other resolutions have taken the 4096x2304 as their base now.

So 573.55 MHz pixel clock works but 583.68 MHz (59 Hz vertical scan rate/refresh) does not? That may be related to DisplayPort 1.2's 576 MHz pixel clock limit for 10bpc RGB.

 

[JaraCz]

If anyone owns Mac Pro 2013 and has money for Apple Studio Monitor, then he should probably buy new computer than new display

 

[joevt]

So 573.55 MHz pixel clock works but 583.68 MHz (59 Hz vertical scan rate/refresh) does not? That may be related to DisplayPort 1.2's 576 MHz pixel clock limit for 10bpc RGB.

That would mean it's not allowing an 8bpc mode which is sad. A dump from AllRez might give more info.
The general info tab showed a max pixel clock of 667 MHz. I wonder what that's related to.

 

[IsaacFOK]

That would mean it's not allowing an 8bpc mode which is sad. A dump from AllRez might give more info.
The general info tab showed a max pixel clock of 667 MHz. I wonder what that's related to.

Happy to do some tests if it would help?

 

[IsaacFOK]

If anyone owns Mac Pro 2013 and has money for Apple Studio Money, then he should probably buy new computer than new display

Why? My MP6.1 is a recent purchase due to the need of using a powerful mac, thats compact, cheap and Intel based. I also bought a 5k LG monitor for the setup, its been excellent for my work flow which is not graphics or video editing.

 

[JaraCz]

Because it is too expensive to be paired with 10 years old device.

 

[Amethyst1]

Because it is too expensive to be paired with 10 years old device.

People can pair "expensive" displays etc. with whatever device they want.

 

[IsaacFOK]

Because it is too expensive to be paired with 10 years old device.

Well mines was manufacured in 2019......

Anyway, the higher res displays are better for my eyes and concentration, thats worth it alone for me.

 

[IsaacFOK]

Higher quality HMI is always the better option, regardless what it's paired with.