Custom Resolution Utility (CRU)

[ToastyX]

(12-17-2020 02:18 PM)mathieulhe Wrote:  So, I did some more extended tests on the EDID profile you shared, although it does work properly, if I go to the hidden hdmi diagnostic menu on the LG CX, using the new EDID, even at 2160p 10 bit 120hz (using 4*10gbps lanes as if I was using the original EDID), I get a lot of PHY errors in the hdmi data stream compared to when using the default EDID, did you do anything other than incrementing the FRL?

I only changed the maximum FRL rate. CRU also doesn't include the range limits by default except with FreeSync monitors, but that doesn't affect any functionality. HDMI 2.1 VRR is in the HDMI 2.x data block.

[ToastyX]

(12-17-2020 11:28 AM)jarkid Wrote:  Could you please tell me
1. What's the probable reason that "LCD reduced" would make my screen to flicker?
2. Why does the default setting of 75 Hz use "LCD reduced" as I see in CRU? It's made by Windows or my monitor manufacturer?
Thanks a lot !!!

Your "good" timing parameters match "LCD native", not "LCD standard". The default timing parameters match "LCD standard", not "LCD reduced". The default timing parameters are set by the monitor's manufacturer in the monitor's EDID, which is what CRU shows. If the monitor can't handle the default timing parameters, then that's a monitor fault. It might be an issue with FreeSync not working correctly.

[traderdude123]

Hi toastyx,

I capture these shots from my TVs hdmi diagnostics screen after using the lg_cx_48Gbps.dat

https://ibb.co/myQGkTw

https://ibb.co/QpHympm

Any idea what they mean?

Should i be worried about the error count?

[jarkid]

(12-17-2020 04:10 PM)ToastyX Wrote:  

(12-17-2020 11:28 AM)jarkid Wrote:  Could you please tell me
1. What's the probable reason that "LCD reduced" would make my screen to flicker?
2. Why does the default setting of 75 Hz use "LCD reduced" as I see in CRU? It's made by Windows or my monitor manufacturer?
Thanks a lot !!!

Your "good" timing parameters match "LCD native", not "LCD standard". The default timing parameters match "LCD standard", not "LCD reduced". The default timing parameters are set by the monitor's manufacturer in the monitor's EDID, which is what CRU shows. If the monitor can't handle the default timing parameters, then that's a monitor fault. It might be an issue with FreeSync not working correctly.

Dear ToastyX,

I appreciate you very much.

So my default timing parameters for 60 Hz is "LCD native", and the other(75 Hz) is "LCD standard".

Then could you figure out that

1. Why does the manufacturer use different timing parameters for 60/75 Hz? or in fact, the most common parameters for 75 Hz or higher refresh rates is "LCD standard"?
2. Why is "LCD native" 75Hz good compared to "LCD standard" 75Hz? Or is that because my video card can't handle "LCD Standard" 75hz well?

I turned off the FreeSync in the AMD software for the specified application, but the flickering had still existed. so I can't tell if that was caused by FreeSync.( My monitor's OSD menu doesn't have FreeSync, but it supports that in the spec.)

[ToastyX]

(12-18-2020 01:30 AM)jarkid Wrote:  So my default timing parameters for 60 Hz is "LCD native", and the other(75 Hz) is "LCD standard".

Then could you figure out that

1. Why does the manufacturer use different timing parameters for 60/75 Hz? or in fact, the most common parameters for 75 Hz or higher refresh rates is "LCD standard"?
2. Why is "LCD native" 75Hz good compared to "LCD standard" 75Hz? Or is that because my video card can't handle "LCD Standard" 75hz well?

"LCD native" is the same as "LCD standard" at 60 Hz. Both 60 Hz and 75 Hz are using standard timing parameters by default. The problem is the monitor. It should have no problem handling the default timing parameters. There's really no reason for "LCD native" to work better. That actually uses more bandwidth, so it's not a signal quality problem.

[ship1666]

(12-17-2020 09:42 AM)ship1666 Wrote:  

(12-17-2020 02:18 AM)ship1666 Wrote:  [quote='ToastyX' pid='11468' dateline='1608148176']
[quote='ship1666' pid='11461' dateline='1608103716']
I attach the adaptor picture here. I use three of them connecting to my RTX3080, it is just a normal cheap adaptor.

I am also curious that the problem comes from the adaptors. Therefore, I am looking forward to get two 2.1 hdmi to testing two screens surround (my GPU has only 2 hdmi ports) If it works, it means the problem comes from adaptors right? If it work, I plan to use 2 hdmi port and 1 display port to run triple screens. Therefore, I have to find one more reliable adaptor.

From your experience, can you suggest the adaptor (display port to hdmi) that works with NV surround? I find one from Club3d (display port to 2.1 hdmi). I am not sure it is gonna work or not.

That looks like a passive adapter. The problem isn't the adapter itself, but the GPU might have a limitation that won't allow Surround to work with three screens with passive adapters, although I can't find any information about such a limitation with NVIDIA cards. I know AMD cards have such a limitation with Eyefinity. Passive adapters also won't allow the full HDMI 2.1 bandwidth. The Club3D adapter should work since it's an active adapter.

Hi ToastyX

In my case, do you think I need 3 active adaptors DP to HDMI, or just 1 active adaptor and 2 HDMI cables? Which way is gonna be work with NV surround.

Thank you, ToastyX

[ToastyX]

(12-17-2020 06:50 PM)traderdude123 Wrote:  I capture these shots from my TVs hdmi diagnostics screen after using the lg_cx_48Gbps.dat

https://ibb.co/myQGkTw

https://ibb.co/QpHympm

Any idea what they mean?

Should i be worried about the error count?

I don't know. Maybe the hardware or firmware can't handle a 48 Gbps signal without errors. That might be why it's limited to 40 Gbps by default.

[ToastyX]

(12-18-2020 03:00 AM)ship1666 Wrote:  In my case, do you think I need 3 active adaptors DP to HDMI, or just 1 active adaptor and 2 HDMI cables? Which way is gonna be work with NV surround.

I don't know. Either way, you'll need the HDMI cables, so try it with one adapter first.

[mathieulhe]

(12-18-2020 03:16 AM)ToastyX Wrote:  

(12-17-2020 06:50 PM)traderdude123 Wrote:  I capture these shots from my TVs hdmi diagnostics screen after using the lg_cx_48Gbps.dat

https://ibb.co/myQGkTw

https://ibb.co/QpHympm

Any idea what they mean?

Should i be worried about the error count?

I don't know. Maybe the hardware or firmware can't handle a 48 Gbps signal without errors. That might be why it's limited to 40 Gbps by default.

The thing is, this happens even at 40gbps as soon as we apply the modified EDID. If we revert to the original EDID, still running at the same resolution and lane speed, the errors stop.

I see only 2 bytes were changed from the original EDID, I am not sure if byte 0xC6 (increment of +0x10 compared to the original) is only the FRL (are they using a bitmask? I assume byte 0xFF is a parity byte, are you sure it's properly calculated ? (I assume so, since the additional 0x10 from the modified byte is subtracted from the parity byte so it seems to be a sum)
I never looked into modifying EDID by hand before.

[jarkid]

(12-18-2020 02:56 AM)ToastyX Wrote:  

(12-18-2020 01:30 AM)jarkid Wrote:  So my default timing parameters for 60 Hz is "LCD native", and the other(75 Hz) is "LCD standard".

Then could you figure out that

1. Why does the manufacturer use different timing parameters for 60/75 Hz? or in fact, the most common parameters for 75 Hz or higher refresh rates is "LCD standard"?
2. Why is "LCD native" 75Hz good compared to "LCD standard" 75Hz? Or is that because my video card can't handle "LCD Standard" 75hz well?

"LCD native" is the same as "LCD standard" at 60 Hz. Both 60 Hz and 75 Hz are using standard timing parameters by default. The problem is the monitor. It should have no problem handling the default timing parameters. There's really no reason for "LCD native" to work better. That actually uses more bandwidth, so it's not a signal quality problem.

"That actually uses more bandwidth, so it's not a signal quality problem."

But this page tells that:
"LCD native" just uses the 60 Hz "LCD standard" timing parameters for all refresh rates. This works better when adding higher refresh rates with some LCD monitors and TVs. This is also what is filled in by default when clicking the "Add..." button.
https://forums.guru3d.com/threads/cru-cu...rt.410187/

What if more bandwidth gives better signal quality...etc?