Monitor Tests Forum

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]But i know this is BS because there seems to be a limit where if the total pixel clock exceeds a specific value, vram clocks will switch to high because there is no other intermediary powerplay clock state to support that total bandwidth..It's 2022 and multimonitor high resolution/bandwidth users still get f*cked over with this. Nvidia does it too. They will never learn it looks like it.

The memory clock issue has nothing to do with bandwidth. Changing the memory clock while the screen is refreshing will corrupt the image while the memory is being retrained, so the memory clock needs to change during the vertical blanking period to avoid this. If the vertical blanking period is not long enough, there won't be enough time to finish retraining the memory before the next refresh starts. That's why the memory clock won't change if the vertical blanking is too low. That's for a single monitor. For memory clock changes to work with multiple monitors, both monitors must be perfectly synchronized so the vertical blanking period happens at the same time, otherwise there's no way to avoid corrupting the image on one of the monitors. You have to make sure that the timing parameters for the detailed resolutions for both monitors match exactly. If they do match and it still won't clock down, then that's a driver bug or hardware-specific limitation. There should be no issues with clocking down with two identical monitors at 2560x1440 @ 144 Hz if the vertical blanking is long enough. What happens if you try 8 bpc color instead of 10 bpc?

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]The issue i am having is that while at factory timings 1440p@144hz@10bit both monitors will run HBR3 (4x8.1Gbps) all day, everyday at all scenarios, anything i've tried over that it will work but when the monitor is turned off (like windows display sleep timeout) and then you wake it up that will force DP link re-training, it will run into some kind of safe mode where it drops down bitrate to 6bit and HBR2 even though it just did work just fine before. I can see that quite easily because any color gradient shows visible banding.

When this happens in the radeon settings it will make bit depth option disappear, and windows resolution information in settings will still show 10bit when it's clearly not. To recover from here i need to drop to 120hz (which is one of the standard monitor modes, not a custom one) change bit depth to 8bit, then switch back to my overclocked setting and re-set to 10bit and it will stay at HBR3 until DP link retraining is initiated again. This method works 100% consistently but i could also just switch to 120hz and back without changing bit depth but this doesn't have 100% success.

I've tried different timings but i couldn't find any settings that will prevent this from happening. Also changing the "Voltage swing" and "PreEmphasis" overrides didn't make any difference. However i've noticed a couple of other weird things. First i get a 3rd entry of this monitor in CRU with the factory edid conf that is never active, and when it swiches to HBR2 6bit from HBR3 10bit the actual refresh rate changes (example from 150hz to 149.9xxxhz)

My guess this happens because it tries to do some kind of quick DP link re-training and it fails, so it switches to HBR2, but since it can't do that refresh rate at that resolution it reduces bitrate to minimum and re-tries (since it should be possible to run it at 8bit, but it skips that entirely).

If the EDID actually changes when this happens, then this is something the monitor is doing, not the GPU. My guess is the monitor might have a firmware bug that causes it to be in HBR2 mode (1.4 disabled) when waking up from sleep. DisplayPort automatically downgrades the color depth if there's not enough bandwidth.

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]Running stock settings HBR3 144hz: https://i.imgur.com/N5VLZkL.png
Some reference timings at 150hz: https://i.imgur.com/smJskaU.png (weirdly here it says CVT timings will fit into HBR3 but CRU locks you well before that, why??)

Vertical front porch can't be higher than 63 for EDID detailed resolutions, and the pixel clock can't be higher than 655.35 MHz. You can use a DisplayID extension block to add detailed resolutions with higher limits.

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]Also i have one more general question..when overclocking a freesync monitor you need to increase the freesync range in order for it to work up to the new overclocked refresh rate or not? Also. does the pixel clock limit you can edit there play any role? (i did increase those in my case if it's relevant)

You need to increase the range if you want FreeSync to work at the higher refresh rate. Some monitors handle higher refresh rates differently with FreeSync than without, like frame skipping if the refresh rate is not within the range. The pixel clock limit doesn't affect FreeSync, but AMD's driver will ignore any resolutions higher than the limit, so you should increase it if you're adding a detailed resolution with a higher pixel clock. The pixel clock value must be a multiple of 10, and the HBR3 limit is 1080 MHz, so you can just use that.

(11-30-2022 11:08 PM)Jaytie Wrote: [ -> ]I used CRU quite a long time ago and just came back to it, with a new task, great tool after all :
So I'm also using a 42" 16:9 4K display. I created a custom 21:9 resolution (namely 3840x1600). When creating this relolution with "no scaling" activated the picture is centered.
What I try to achive is that the picture is displayed at the bottom of the screen instead of centered in the middle. Since I could not find anything about it: Can CRU do this?

No, there's no way to control positioning with CRU. It would have to be done through the GPU, but I don't know any GPU that provides this feature.

(11-30-2022 09:16 AM)patrickge Wrote: [ -> ]it's just an 6bit Panel build in.... this one: https://www.panelook.com/B156HAN02-1-AUO...76737.html

anyway i cant even change to 70 or 80hz for example. weird...

Even with a 6-bit panel, the color depth is normally 8 bpc, and the panel usually dithers to simulate 8 bpc. I don't see why 90 Hz would show up but not 70 or 80. That has to be a driver bug. Make sure you are using detailed resolutions, not standard resolutions. Standard is like using "Automatic CRT" which uses higher pixel clocks.

(12-01-2022 07:42 PM)ToastyX Wrote: [ -> ]No, there's no way to control positioning with CRU.

Okay, it was worth a try. Thank you for answering!

(12-01-2022 11:09 AM)dsir67 Wrote: [ -> ]

(11-29-2022 07:11 PM)ToastyX Wrote: [ -> ]

(11-28-2022 02:16 PM)dsir67 Wrote: [ -> ]Hello, I've been having a problem with new LG oled C2 and my RTX3060 video card. I came across this CRU utility and website and am hoping someone here can help.

I've been beating this up for a couple weeks now, and although some progress has been made I'm still not where I need to be. The entire detailed thread on avsforum is here: https://www.avsforum.com/threads/new-lg-...t-62116130

Reverting to a specific older Nvidia driver helped some of the issues, but at the end of the day I am still unable to choose any 4K PC resolutions above 60Hz in the NCP. The TV goes dark and says no signal. I can VNC into the PC and see the desktop. The computer itself will accept the 100/120Hz 4K settings when they are selected, the TV just loses sync.

I ran the CRU utility and exported the EDID. Have attached to this post. Hoping there is useful info in there, or someone here has some ideas. AM open to all suggestions.

Honestly, it sounds like there's a hardware problem somewhere because this setup should work without problems. The EDID is fine, and the PC recognizes the resolutions, so the signal is getting distorted somewhere. You mentioned trying other cables, so I think either the video card or the TV is defective. If the video card has another HDMI port, try that just in case the HDMI port is bad. Try another HDMI port on the TV as well.

Thank you for the help and checking the EDID. Did try all ports on the TV. I'm leaning toward the card/hdmi port being culprit. Unfortunately I only have one HDMI and 3DP. I purchased a Displayport to HDMI adaptor and can now achieve 120Hz@4K.

Hey to interject, it's normally the Driver on Nvidia side.

For instance, with the latest Nvidia Driver 526.98 Game version, some features, have been removed in the drop menu for each individual choice and then added a few in other choices for Manage 3D .

I disagree with ToastyX on hardware being the issue. A new driver doesn't always prove to be of best interest. If you have problems with a newer driver, such as something stops working, go back to the driver where it was working.

With the addition in Windows 11 22H2 for Graphics section in Display, there are at least 4 new additions depending on the graphics card one is using.
VRR is one of them. This plays havoc because it is relatively new and has not been stable. Flickering issues happen on G-SYNC Freesync monitors. Not necessarily the hardware here. But the software. The issue is getting the software to work with the hardware.
If your tv or monitor does display a screen and can watch tv shows in normal mode--broadcast from Satellite or Cable then there is nothing wrong there. But if you have refresh rate issues when plugged into a graphics card, and you do get normal broadcast tv shows, movies, and cannot raise the freq in the card, but the card is rated for 120Hz when plugged into HDMI or DP, then the issue is driver. Process of elimination in troubleshooting.

Driver's are not perfect and are a series of patches one from next, to turn on or off some new or not working well features as prescribed by the Manufacturer of said graphics card. Buying an additional unit to make it work is not the answer either. It it working to find a driver that works well with your hardware.

Software is a always in a development stage regardless of what anyone states and is not perfect. Thus rollback may be necessary to find what works in your case.

To see what new drivers accomplish with options that are not previous or improved on some features is a good thing. Then take notes.

(12-01-2022 07:42 PM)ToastyX Wrote: [ -> ]

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]But i know this is BS because there seems to be a limit where if the total pixel clock exceeds a specific value, vram clocks will switch to high because there is no other intermediary powerplay clock state to support that total bandwidth..It's 2022 and multimonitor high resolution/bandwidth users still get f*cked over with this. Nvidia does it too. They will never learn it looks like it.

The memory clock issue has nothing to do with bandwidth. Changing the memory clock while the screen is refreshing will corrupt the image while the memory is being retrained, so the memory clock needs to change during the vertical blanking period to avoid this. If the vertical blanking period is not long enough, there won't be enough time to finish retraining the memory before the next refresh starts. That's why the memory clock won't change if the vertical blanking is too low. That's for a single monitor. For memory clock changes to work with multiple monitors, both monitors must be perfectly synchronized so the vertical blanking period happens at the same time, otherwise there's no way to avoid corrupting the image on one of the monitors. You have to make sure that the timing parameters for the detailed resolutions for both monitors match exactly. If they do match and it still won't clock down, then that's a driver bug or hardware-specific limitation. There should be no issues with clocking down with two identical monitors at 2560x1440 @ 144 Hz if the vertical blanking is long enough. What happens if you try 8 bpc color instead of 10 bpc?

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]The issue i am having is that while at factory timings 1440p@144hz@10bit both monitors will run HBR3 (4x8.1Gbps) all day, everyday at all scenarios, anything i've tried over that it will work but when the monitor is turned off (like windows display sleep timeout) and then you wake it up that will force DP link re-training, it will run into some kind of safe mode where it drops down bitrate to 6bit and HBR2 even though it just did work just fine before. I can see that quite easily because any color gradient shows visible banding.

When this happens in the radeon settings it will make bit depth option disappear, and windows resolution information in settings will still show 10bit when it's clearly not. To recover from here i need to drop to 120hz (which is one of the standard monitor modes, not a custom one) change bit depth to 8bit, then switch back to my overclocked setting and re-set to 10bit and it will stay at HBR3 until DP link retraining is initiated again. This method works 100% consistently but i could also just switch to 120hz and back without changing bit depth but this doesn't have 100% success.

I've tried different timings but i couldn't find any settings that will prevent this from happening. Also changing the "Voltage swing" and "PreEmphasis" overrides didn't make any difference. However i've noticed a couple of other weird things. First i get a 3rd entry of this monitor in CRU with the factory edid conf that is never active, and when it swiches to HBR2 6bit from HBR3 10bit the actual refresh rate changes (example from 150hz to 149.9xxxhz)

My guess this happens because it tries to do some kind of quick DP link re-training and it fails, so it switches to HBR2, but since it can't do that refresh rate at that resolution it reduces bitrate to minimum and re-tries (since it should be possible to run it at 8bit, but it skips that entirely).

If the EDID actually changes when this happens, then this is something the monitor is doing, not the GPU. My guess is the monitor might have a firmware bug that causes it to be in HBR2 mode (1.4 disabled) when waking up from sleep. DisplayPort automatically downgrades the color depth if there's not enough bandwidth.

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]Running stock settings HBR3 144hz: https://i.imgur.com/N5VLZkL.png
Some reference timings at 150hz: https://i.imgur.com/smJskaU.png (weirdly here it says CVT timings will fit into HBR3 but CRU locks you well before that, why??)

Vertical front porch can't be higher than 63 for EDID detailed resolutions, and the pixel clock can't be higher than 655.35 MHz. You can use a DisplayID extension block to add detailed resolutions with higher limits.

(12-01-2022 08:15 AM)TnF Wrote: [ -> ]Also i have one more general question..when overclocking a freesync monitor you need to increase the freesync range in order for it to work up to the new overclocked refresh rate or not? Also. does the pixel clock limit you can edit there play any role? (i did increase those in my case if it's relevant)

You need to increase the range if you want FreeSync to work at the higher refresh rate. Some monitors handle higher refresh rates differently with FreeSync than without, like frame skipping if the refresh rate is not within the range. The pixel clock limit doesn't affect FreeSync, but AMD's driver will ignore any resolutions higher than the limit, so you should increase it if you're adding a detailed resolution with a higher pixel clock. The pixel clock value must be a multiple of 10, and the HBR3 limit is 1080 MHz, so you can just use that.

Thanks a lot for the reply.
I actually found the issue. I made this device a year ago to trick the GPU to still output video signal when you turn off the monitor, so it doesn't re-arrange your windows and stuff. You can only do this on Quadro/Radeon Pro cards by doing edid emulation, but it's not available on consumer cards. Some monitor offer this option in their menu but i've only seen it on workplace kind of monitors. There is no such product in the market for DP, there is only for HDMI where the implementation is much easier.

So what happens (depending on the monitor) they might follow DP specs on the implementation or do whatever they want. It looks like not even GPU's follow it, or something was changed since i do not have access to the latest standard, only to v1.2. Normally when the monitor turns off (downstream device) it should notify the gpu (upstream device) so it cuts off transmission, and when the monitor it's powered on again it should notify the gpu to re-train the DP link and start transmitting again. The 27GL850's i have of the latest revision follow this spec, but for example the first revision 27GL850 i had didn't (you would power it off and it would still show as powered on to the gpu, and only when you powered it on again it would do retraining..)

This is handled on the HPD line, and there is specific range of timing duration for the pulses done to communicate. For example the timing is too short the gpu will not detect that a monitor was powered on and it will not output video signal. In this case here what happens is that it looks like when you already have established a link with the monitor and you change resolution, or wake the monitor from sleep a different kind of quick re-training happens, and if the pulse is too long, the AMD gpu drivers will think that the monitor failed to accept the resolution and it will drop down to lower data rate. And since the 10bit signal didn't fit in HBR2 it drops bitrate to 6 bit (or just goes there straight as "safe mode"; impossible to tell only AMD knows).

Anyways by adjusting the pulse duration i was able to find a happy medium that works in all cases..this is a temp solution however as other monitors/gpus might behave differently. So i need to re-write my code to detect this kind of "quick link re-training" and adjust accordingly. For now i tested it the whole weekend and it worked 100% perfectly.

I also made a version of this device that should theoretically be able to emulate edid in hardware but i haven't wrote any code to test it. I want to finish other projects first.

Regarding the vram clocks:

I've checked the vertical blanking and it's more than enough, tried exact values, increased further etc, i only get idle vram clocks when i run:
- 1x monitor 1440p@10bit@144hz
- 2x monitors 1440p@10bit@60hz
Anything more i get full vram clk.

Hello. I must be doing something wrong because I can't get this to work. I have an LG monitor. I installed Windows 10 fresh on an old computer running an old Geforce GTX470 card.
Windows recognizes my monitor as LGE2250 however it only lets me have 1280X1024 as my maximum resolution when the max for this monitor is 1920X1080 60hz.
When I use this application it shows the correct resolution as the detailed resolution (1920X1080 60hz).
When I click OK and run the restart program it doesn't change the resolution and when I go into display settings the LG profile is not recognized anymore and is replaced by "Display 1: Wired Display" now and the resolution is greyed out and I can't change it at all anymore.
When I go back into this program it now shows two monitor profile choices (the LG and "generic non-pnp" monitor.
What am I doing wrong?
Also, I tried updating my graphics card and when I try to download the latest driver it bricks my system so I gave up on that. Same if I try to update with Windows Update.
Also, downloaded the supposed latest driver from the LG website but none of the files seem to be an actual update that I can execute.
Like I said, I'm sure I'm doing something wrong but I have no idea what. Any help?

(12-07-2022 04:29 AM)Carnage6 Wrote: [ -> ]Hello. I must be doing something wrong because I can't get this to work. I have an LG monitor. I installed Windows 10 fresh on an old computer running an old Geforce GTX470 card.
Windows recognizes my monitor as LGE2250 however it only lets me have 1280X1024 as my maximum resolution when the max for this monitor is 1920X1080 60hz.
When I use this application it shows the correct resolution as the detailed resolution (1920X1080 60hz).
When I click OK and run the restart program it doesn't change the resolution and when I go into display settings the LG profile is not recognized anymore and is replaced by "Display 1: Wired Display" now and the resolution is greyed out and I can't change it at all anymore.
When I go back into this program it now shows two monitor profile choices (the LG and "generic non-pnp" monitor.
What am I doing wrong?
Also, I tried updating my graphics card and when I try to download the latest driver it bricks my system so I gave up on that. Same if I try to update with Windows Update.
Also, downloaded the supposed latest driver from the LG website but none of the files seem to be an actual update that I can execute.
Like I said, I'm sure I'm doing something wrong but I have no idea what. Any help?

Post a screen shot of Device Manager that shows what's under display adapters and monitors.

Hello and thank you very much for this amazing tool and support!

Monitor: AOC Q3279VWFD8
GPU: Sapphire Nitro+ RX 480 8GD5 (UEFI) SKU number: 11260-07
Connection: DisplayPort cable that came with monitor, using 10bit color depth.
Windows 11 22H2 , Latest AMD driver (atm 22.11.2) [I have created the custom resolution in CRU and not in AMD driver settings, idk if its correct?]
CRU settings: Look in screenshots

Stock @75hz (which does not seem to follow the VESA standard)
[attachment=1041]

My over/under-clocked @76hz, changed freesync also from 48-75 to 38-76
[attachment=1042]
[attachment=1043]

My target is to get the "correct/best" settings for my monitor to achieve "LFC" (which requires the maximum freesync range to be at least x2 of the minimum freesync range).
I have it already working except a weird "tear/stuttering" that happens at ~@38fps probably because it is just about double and not even 1hz more as I get blank screen above 76.1/76.2 Hz.

But I am not sure if the monitor timings are correct and maybe hurting something

Thank you for this tool.

I have been trying to figure out a FEW problems that I have been facing but wasn't aware of, and then later I realized there are problems and I couldn't solve them with native nvidia apps and window settings, until I found CRU.

TLDR : Active Signal Resolution is what the PC/GPU is receiving/interpreting the EDID from the monitor.
(I did not (want to spend any more time) read up the relationships/connections of these specific technologies to know which the words to use. Its what I came to interpret. In any case, my current understandings solved my issues.)

If the Active Signal Resolution is wrong, it causes a variety of problems.
- wrong native resolution
- unable to utilize your monitor's highest refresh rate
- alt-tab when returning from desktop back to game zoomed in the display in the game, changing the centre of your display location and your mouse centre location changes, forcing to close the game and restart or forcing to use windowed mode unable to utilize Nvidia Image Scaling.
- very low fps in games, even with super low graphic settings and resolution

I happened to accumulate and face all of them at the same time without knowing its from one source. Thankfully they are all linked.

Use CRU to force edit the right EDID for the PC/GPU so that your games/app/desktop runs at the correct native resolution and highest refresh rate possible, and your games get back higher fps and graphic settings and alt-tab works correctly for games that with link to your native resolution.



#############
My hardware :
Primary Monitor : BenQ EX2780Q (2560x1440p native (2.5K) @ 144Hz max refresh rate)
Secondary Monitor : Dell 2740L (1920x1080p native @ 60Hz max refresh rate)
GPU : RTX3080
CPU : AMD R5 3600

Issue 1 : I am not sure at what point in the 3 years since I built my new PC, did my 2560x1440 (2.5K) native resolution monitor begin to take in 3840x2160 (4K) Active Signal Resolution as the native resolution. But I have always set my desktop to either 2560x1440 or 1920x1080. I thought that this would set the base Desktop Resolution.

Issue 2 : my monitor is capable of going 144Hz refresh rate at native 1440p resolution but windows display settings only allow me up to 60Hz. I also did not know why and when did this changed. I kept my Nvidia drivers updated.

Issue 3 : When Alt-tabbing Fallout 4 from fullscreen to desktop and then go back into the game. The game returns but the display is now zoomed into the top left. The centre is off, mouse pointer is off centre. Many people in reddit reported as well. Game has to closed or use windowed mode which then can't utilize Nvidia Image Scaling.

Issue 4 : I noticed my games has horrendous fps especially when I turn on / increase the graphic settings. I just couldn't understand why when I use the same hardware but other people in their youtube benchmarks always has like double my fps.

I have a few issues to tackle. They seemed to be separate issues but initially I do not know where each of the problem source is. But they all originate from 1 main issue for me and it all linked up my understanding in the end.

The plot twist : Little did I know I have been rendering in 4K (based on what is indicated in Window's Active Signal Resolution) and scaling down everything, games, apps and even desktop resolution. Now it make sense why the "recommended" resolution in my windows display settings is 3840x2160 even if my monitor native is 2.5K. (my monitor can use windows/apps to scale up to 4K at max 60Hz refresh rate).

Somehow the EDID is wrong.

Recently I played some old games like Metro Exodus (2019), Fallout 4 (2015 with HD textures), Red Dead Redemption 2 (2018). Those games are few years old and yet I can't even get consistently 60 fps for all of them, like why man?! Even with low graphics settings and I still have to lower my resolution to 1080p or lower. When I watch other people in youtube with older hardware using the same games to do benchmarks, and get more fps than me with higher graphic settings and higher resolution, that is when I finally know something is very wrong somewhere.

eg. I crank down all my graphic settings and drop resolution to 720p in RDR2 to get 50 fps max
I spent a few hours reading watching and changing Fallout 4 graphic settings into acceptable 40-50 fps.
My low fps in Cyberpunk 2077 was not easily detected because it is a new game and is a graphics intensive game and it did provide a lot of graphic settings to increase fps to acceptable range.

I was playing Fallout 4 with low fps and I also need to Alt-Tab to desktop. I cannot accept having zoomed in display each time i get back in game and have to close the game, so I tried to solve this issue first. I then stumbled upon youtube about "how to increase fps for all games with nvidia settings". I read about NIS (Nvidia Image Scaling) and that we can enable a small overlay indicator ("NIS" text on top left of screen) to display whenever NIS is actively being executed. I was initially wondering why even in my my desktop has this NIS text when I am already setting desktop to my monitor native 1440p resolution.

Then it finally clicked. My desktop is being scaled down to 1440p. This is why my Active Signal Resolution is 4K and my max refresh rate is 60Hz because that's what my monitor limit is capable of. The PC is treating my monitor as native 4K! And the NIS text on desktop is proof. And I use my monitor's HUD information to check the current resolution and refresh rate. It is showing 4K @ 60Hz in all my games!

I have thought maybe my problem sources is to do with windows desktop scaling, or the HDMI cables and versions that I am using, or I need DisplayPort cable, or I need to adjust my Nvidia Control Panel settings or its a dual monitor issue where I need to change to use one monitor only when gaming (which I don't want). I already has all drivers updated. It was driving me nuts with so many trial and errors.

I then do a clean install of Nvidia drivers instead of the usual overwriting installation and low and behold! my 144Hz returns and the windows display settings recommended my monitor native resolution at 1440p. I then enabled NIS and the recommended resolution became 4K and my refresh rate options drop to 60Hz max. Well, that's one way I found that messes with my EDID. I did not try and find what else could have changed my EDID.

When I started up CRU for the 1st time, there is only 1 "detailed resolution" I see and it is 2560x1440 @ 143.something Hz. I supposed this is one of the current EDID resolution.
I created 2 more detailed resolution using Timing as "Automatic PC"
2560x1440 @ 144 Hz
1920x1080 @ 144 Hz

Somehow the NIS text is gone in my Fallout 4. but the Image Scaling option is turned on in Nvidia Control Panel (and can confirm in Geforce Experience as well). When I turn off and on NIS at Nvidia Control Panel, the problems came back. My Active Signal Resolution is 4K. the NIS text appeared on my desktop again. I then try to replicate the solution above but plot twist : it didn't work anymore.

Feelings of annoyance ensues. This is now a new issue. I did not do anything different because I immediately try to use CRU to solve it but it didn't work. I try to reorder and move up my created resolutions in the list of 3 detailed resolutions but nope. I use restart.exe and restart64.exe and reset-all.exe but nope.

But now aside from this new problem where CRU is not changing the EDID, I know where the old problem is which is the EDID is wrong. I know I wanted NIS so I left it being turned on as it is current is, but create problems. I didn't want to clean reinstall nvidia drivers as that will set to default profile which NIS will be turned off. So I try to use CRU timing as "Native PC", it doesn't seem like anything different from "Automatic PC", but this time I also delete the 1 original detailed resolution there, even if it seems like the correct resolution and similar refresh rate and create the 2 detailed resolutions I wanted again.

but guess what, it worked. and I did not try to do anything else after that. because the EDID might get changed again and unable to change back. Having to use CRU twice is indeed puzzling. Until I face the problems again, I will not attempt to try and figure out why.

so my initial issues are ALL solved :
- resolution back to correct native
- refresh rate back up to max capable
- alt-tab fallout 4 has some other graphical settings to change in its .ini files but now i can return to 100% correct display each time
- fps in fallout 4 was 40-50 at low graphic settings. with the native resolution solved and NIS turned on, i get 150-200 fps at ULTRA settings (but note that specifically for fallout 4, need to limit to 60 fps for the in-game timings. I turned off vsync to check if fps is boosted)

what's left : until next episode where I have to use CRU again. (And try the Automatic PC and Native PC timings to see which one works.)