Anyone know if the 7800XT supports FRL6?

N

noatmo

Newcomer
Hey everyone,

I’ve been having an issue with my computer for a while now and I’ve narrowed it down to 2 causes, the primary cause being DSC. My current display just does not like DSC… like at all. So, I’m in a bit of a pickle because for some reason RDNA2 only supports FRL5. That means I’m limited to either 4K144 at 8-bit or 4K120 at 10.

I’m looking to swap out my graphics card now and sell off this 6800XT before it’s value completely tanks. I’m looking at the 7800XT due to pricing. I’ve found a few threads that show that the 7900XTX supports FRL6, but I don’t know if that applies to all RDNA3 cards. I don’t want to order 2 of them for my wife and I’s computer only to find out that it won’t actually fix the problem.

So yeah… Anyone know if the 7800XT supports FRL6 or not?
 
I would be surprised if a lower tier RDNA3 chip would suddenly get a different display PHY.
In other words, N32 should be the same as N31 in its display output capabilities.
 
What display do you need to connect to an RX 7800 XT? I guess it has to use 8K resolution and not-CVT2 timings, or 4K 120+ Hz and 10-bit color depth, to really require FRL6.

I do have an RX 7800 XT card, but I don't have a HDMI 2.1 display (or a HDMI 2.1 lab tester), and AFAIK there's no way to get such low-level details from display driver DDIs in Windows 1x.
 
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Yeah, that's what I figured out after posting the initial comment. Do current OLED TV panels really support 4K 144 Hz 10-bit as a native video mode though? :unsure:
 
DmitryKo said:
What display do you need to connect to an RX 7800 XT? I guess it has to use 8K resolution and not-CVT2 timings, or 4K 120+ Hz and 10-bit color depth, to really require FRL6.

I do have an RX 7800 XT card, but I don't have a 8K HDMI 2.1 display (or a HDMI 2.1 lab tester), and AFAIK there's no way to get such low-level details from display driver DDIs in Windows 1x.
Click to expand...
It's a Corsair 32UHD144. The panel itself is absolutely beautiful. The firmware is complete trash.

Long story short... Adrenaline only shows 8 and 12 bit color when connected via HDMI 2.1. Setting color to 12 bit causes the display to blank black for a frame or 2 every 3ish seconds.
 
Some TVs support 144Hz for a long time (Samsung LEDs for example), this year LG OLEDs will support such mode plus there are 4K monitors which go up to 240Hz - both existing LCDs and upcoming OLEDs.

The question is though whether a GPU with 48 Gbps port will solve the issues which the OP has with the monitor. I'm thinking that this is somewhat unlikely.

noatmo said:
Long story short... Adrenaline only shows 8 and 12 bit color when connected via HDMI 2.1. Setting color to 12 bit causes the display to blank black for a frame or 2 every 3ish seconds.
Click to expand...
Did you try connecting via DP? Or a different HDMI cable?
 
DegustatoR said:
Some TVs support 144Hz for a long time (Samsung LEDs for example), this year LG OLEDs will support such mode plus there are 4K monitors which go up to 240Hz - both existing LCDs and upcoming OLEDs.

The question is though whether a GPU with 48 Gbps port will solve the issues which the OP has with the monitor. I'm thinking that this is somewhat unlikely.


Did you try connecting via DP? Or a different HDMI cable?
Click to expand...
Tried display port. It causes an issue where it will continually register a device being disconnected and reconnected everytime the monitor goes into standby. So it makes the windows device noises roughly every 20 seconds and wakes the monitor back up.

I have new HDMI 2.1 cables on the way from monoprice.
 
Sorry for double posting.. I'm not sure how to edit posts on here.

I tried my wife's old 3060ti which has FRL6 and it showed 8, 10 and 12-bit color at 144Hz. I didn't leave it on long enough to see if it still had the standby issue, but it worked fine outside of that.
 
I've read that there was some issues with RDNA 2 and HDMI... Specifically involving FRL and TMDS. Is it possible that the solution is the same either way?

From what I've read doing some quick searches, it seems like they've largely resolved the issues with RDNA 3. Would I be better off just getting a new card rather than holding my breath waiting for AMD to fix the issue?

Plus it would have added benefit of eliminating the need for DSC.
 
AVSForum has a DP 2.1 / HDMI 2.1 information thread and they assume that
  • RX 7000 series support HDMI 48 Gbps (FRL6) and DisplayPort 54 Gbps (UHBR 13.5)
  • RX 6000 series support HDMI 40 Gbps (FRL5) and DisplayPort 40 Gbps (UHBR 10)
4K @ 144 Hz 10-bit color requires 40.2 Gbps using standard CVT-RB timing formula, so this mode seems out of range for RX 6000 without DSC compression; that said, fixed-resolution displays often use custom timings instead of the pre-defined timing formula, so tighter timings and/or a lower refresh rate could fit under the 35.5 Gbps limit (before 16b/18b encoding overhead of 12.5%).

Please download EnTech MonInfo and post thr EDID preferred timing here - for example, my BenQ EW3270U looks like this:
Code: 
Timing characteristics
  Native/preferred timing.. 3840x2160p at 60Hz (16:9)
    Modeline............... "3840x2160" 533,250 3840 3888 3920 4000 2160 2163 2168 2222 +hsync -vsync
 
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Sure, but lack of 10-bit color mode is probably a driver issue that could be resolved by AMD. The question was whether RX 7000 series would make a difference with this specific monitor - if it uses either custom reduced timings, similar to the most recent CVT-RB v3, or a slightly reduced refresh rate, 10-bit color 4K @ 144 Hz would fit well into the 40 Gbps video bandwidth limit of the RX 6000 series. If it doesn't, the OP needs RX 7000 and 48 Gbps bandwidth to use 10 bit color in 4K @ 144 Hz mode.
 
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DmitryKo said:
Sure, but lack of 10-bit color mode is probably a driver issue that could be resolved by AMD. The question was whether RX 7000 series would make a difference with this specific monitor - if it uses either custom reduced timings, similar to the most recent CVT-RB v3, or a slightly reduced refresh rate, 10-bit color 4K @ 144 Hz would fit well into the 40 Gbps video bandwidth limit of the RX 6000 series. If it doesn't, the OP needs RX 7000 and 48 Gbps bandwidth to use 10 bit color in 4K @ 144 Hz mode.
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Well.. Is there a way for me to check the timings to tell you what it's running? Would that stuff be in the EDID?

This is what I see in Adrenaline. I can grab CRU if needed.
 

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All monitors specify their supported/preferred timings in the EDID structure that's transmitted to the video card, which could be read by MonInfo; the timings reported by the Adrenalin driver should be fine too. We only need pixel clock to calculate the bandwidth.

These timings look tighter than CVT-RB v3 formula for 4K @144 Hz, however the effective pixel bandwidth for 10 bit color mode is still 1265 MHz x 30 bit = 37.95 Gbit/s, which needs 42.7 Gbps of transmission bandwidth if you consider 16b/18b encoding of the FRL mode (12.5% overhead). It would work fine if your monitor supported DisplayPort 40 Gbps (UHBR 10), which uses 128b/132b encoding (3.1% overhead) so the transmission bandwidth would be 39.15 Gbps.
 
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DmitryKo said:
All monitors specify their supported/preferred timings in the EDID structure that's transmitted to the video card, which could be read by MonInfo; the timings reported by the Adrenalin driver should be fine too. We only need pixel clock to calculate the bandwidth.

These timings look tighter than CVT-RB v3 formula for 4K @144 Hz, however the total for 10 bit color mode is still 1265 MHz x 30 bit = 37.95 Gbit/s, which needs 42.7 Gbps of transmission bandwidth if you consider 18b/16b encoding of the FRL mode. This would be fine if your monitor supported DisplayPort 40 Gbps (UHBR 10) which uses 132b/128b encoding.
Click to expand...
Will it work with FRL6 without compression? If I'm understanding things correctly FRL6 supports 41.92Gbit/s and 48 including overhead, right?
 
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