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Drivers & Software

disi
Adept III

Displayport 1.4 link speed and HBR3

I have a monitor capable of DP 1.4 HBR3

I have AMD Vega capable of DP 1.4 HBR3

I have a DP cable capable of DP 1.4 HBR3

What do you need to do, to have a faster link than:

Current Link Settings

5.4 Gbps x 4

Shouldn't this be 8.1 Bbps HBR3?

It can do 4K@60Hz and HDR turned on.

17 Replies
mudkips
Adept I

Re: Displayport 1.4 link speed and HBR3

I have a similar issue. I have an RX 470 on 19.2.2 in Windows 7 x64 and a new AOC AG273QCX which should support 2560x1440 @ 144 Hz and 10 bpc.  However I can only get it to run at 2560x1440 @ 144 Hz and 8 bpc or 2560x1440 @ 120 Hz and 10 bpc.  I'm using the cable supplied in the box.  I can only ever see 4x 5.4 Gbps lanes in use via Radeon Settings.  This correlates to DP 1.2, and not the HBR3 mode available on DP 1.3 and above.

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disi
Adept III

Re: Displayport 1.4 link speed and HBR3

I bought this cable then and get 4x5.4 Gbps on DP (before this only showed via HDMI):

https://www.amazon.co.uk/dp/B0767F5DNR?ref_=pe_747761_41185591_dpLink 

However the speed is the same as with HDMI 4x5.4 Gbps. I do now have the option to change to 10bpc, but it doesn't stick.

I do run a dual monitor setup with some smaller less capable monitor, maybe this is the issue.

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jdrobinson314
Challenger

Re: Displayport 1.4 link speed and HBR3

Have you installed the ICC profile for your monitor disi ? This is something I had to do with my LG displays. Though I do not have a 144hz monitor... Maybe try adding the ICC profile from your monitor's website. This is sort of a task in and of itself that not a lot of people do - generally, they just toss that disc that came with the monitor aside and call it good. Plug and play, right? Windows 10 updates have been ill managed when it comes to fetching these color profiles from updates.

mudkips‌, that desired resolution and refresh rate are supported by HDMI 2.0 standard, have you tried an HDMI cable instead? - HDMI would not support the 10 bit depth, however. Related to this recommendation, I've looked all over the AOC website regarding your monitor and cannot find where it supports 10 bit color. I'm only seeing where it supports 16.7 million colors, and that's not 10 bit. Monitor nerds website says otherwise, but the official website does not indicate this. Are you able to get 10 bpp at lower refresh rates or what? And another thing, just in general, from my experience, you might have to jump through a hoop or two to enable Freesync on some displays, even the ones that have it on out of the box - is Radeon telling you that it's on. Or are you telling windows to go to a specific refresh rate in the adapter option?

I have two different 10 bit monitors myself, and they're not true 10 bit panels, they're 8bit+2bit FRC or A-FRC. Radeon Settings didn't see 10 bit color until I installed those color profiles from the manufacturer's website. At this time, Radeon settings is showing me all the correct specs and color settings for the monitors - what it does not show me is the freesync range as conveyed by the manufactures when it comes to available display modes via the adapter options. This is just something I'll have to look up for gameplay + radeon chill or target frame rate control. So, a note about one of my monitors, the LG 27uk600 - it supports HDR/WCG, and it looks amazing when viewing HDR content - but the picture adjustments are locked down like you wouldn't believe because that monitor only has a 1.2DP in the back. I found that getting the 10 bit working and setting my color preferences close to REC709 color was much more visually beneficial than the HDR setting on that monitor.

So I'm getting 4k60 10 bit with and without HDR/WCG frills and that link speed is still saying 5.4 Gb/s - because that's only as much as it needs for that signal. So, disi‌, do you have a 5k+ 10 bit display to plug in? - that would overwhelm the link speed need. The link speed is only ever going to be 5.4 per lane until you need the HBR3 speed. It's an energy saving / error reduction methodology at work here.

I mean, there could be a workaround for the physical hardware, some monitors have super-resolution where you can send a higher resolution that supported and it will down scale it. This could test the link speed for HBR3 availability.

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mudkips
Adept I

Re: Displayport 1.4 link speed and HBR3

It's an 8-bit panel physically, with FRC for 10-bit input support.

I can get 10 bpc to stick at 120 Hz or lower, or at 144 Hz with chroma sub sampling).

Basically, everything up to the DP 1.2 limit works. Anything beyond it does not.

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jdrobinson314
Challenger

Re: Displayport 1.4 link speed and HBR3

Sounds like you're limited by the DP 1.2 interface on your monitor.

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mudkips
Adept I

Re: Displayport 1.4 link speed and HBR3

The monitor supports DP 1.4, and I've confirmed this via the manual and AOC support.

(The USA site's tech specs shows DP 1.2 incorrectly - all other regions for AOC list DP 1.4, the Amazon store page lists 1.4, the product brochure and manual lis 1.4, and support have confirmed that it's 1.4.)

See these related threads.

My monitor supports 10bit but cannot be enabled in Radeon setting 

Windows 10 RGB444 4K 60hz 10bits mode issue 

https://community.amd.com/message/2894536 

jdrobinson314
Challenger

Re: Displayport 1.4 link speed and HBR3

It fails all logic, but you might try a shorter cable if possible. It might be a bandwidth limit for a given length or a bad cable - it doesn't solve the OP's issue.

Other than that, you should still be able to get that refresh rate and bit depth with HDMI 2.0, that monitor supports freesync on both ports.

Otherwise, All I'm seeing is conflicting information on the AOC website. Maybe it can have it's frimware updated, I do not know.

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disi
Adept III

Re: Displayport 1.4 link speed and HBR3

You get the official ICC profile from BenQ website:

colour_management.JPG

It still switches back to 8bpc itself on 4K, 2K and HD.

With the second monitor disconnected it shows the same behaviour.

I am not sure if I even would notice a difference between 8bpc and 10bpc, but I do want to know how and if it works

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jdrobinson314
Challenger

Re: Displayport 1.4 link speed and HBR3

Wonder if there are some settings on the monitor OSD that may be effecting the problem. That model has A B.I. button  Wonder what that does.

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