Memory doesn't downclock on idle (RTX 3080 - Dual 4k 144Hz monitors)

[Vasllo]

It's pulling around 90~100w just idling in my browser or watching videos. My 3060 Ti used much less energy than that. I've got 2x 4k 144Hz HDR monitors, and this is with one turned off. Here's the HWInfo data:

Any way to force the memory to downclock?

 

[Salted Spinach]

6 hours ago, Vasllo said:

I've got 2x 4k 144Hz HDR monitors, and this is with one turned off.

Is there a difference in GPU frequency or power consumption when both are turned on?

 

If the answer is No, it means Windows is still telling the GPU to produce an image for the second monitor. The solution is to disable the extended desktop option in Windows Display Settings

 

Besides that, the only reasonable way to reduce power consumption is to check what frequency the GPU is at when on the desktop, and undervolt the volt curve at that frequency.

 

If you are using Afterburner, you could also create an aggressive undervolt+underclock profile which you can toggle from the taskbar icon when not playing a game.

 

You are going to have to do your own homework if undervolting.

 

Good luck

[Vasllo]

On 5/26/2024 at 3:41 AM, Salted Spinach said:

Is there a difference in GPU frequency or power consumption when both are turned on?

 

If the answer is No, it means Windows is still telling the GPU to produce an image for the second monitor. The solution is to disable the extended desktop option in Windows Display Settings

 

Besides that, the only reasonable way to reduce power consumption is to check what frequency the GPU is at when on the desktop, and undervolt the volt curve at that frequency.

 

If you are using Afterburner, you could also create an aggressive undervolt+underclock profile which you can toggle from the taskbar icon when not playing a game.

 

You are going to have to do your own homework if undervolting.

 

Good luck

 

There's no power difference with both or just one turned on, but it lowers about 10w if I remove the DP cable for the second monitor, which is still over 90w at idle.

 

The core is downclocking as intended when idling or just browsing, but the VRAM still stay pegged at 2500MHz (or 10000MHz in MSI Afterburner) unless I change both monitors to 60Hz. I found comments about this bug going as far back as the GTX 500 series for dual monitors setups, I can't believe this is still a thing. It seems like this is something hard-coded on the drivers, and they're not optimized for my setup.

 

I already have made a custom frequency x voltage curve, but I don't think there is a way to do that for memory frequency.

[Vasllo]

If anyone has this issue in the future, here's the info I collected about it:

 

Gainward told me it's expected behavior on high refresh monitors. This sounds like total BS to me, it's pretty clear it's just shitty drivers from Nvidia that just do this as a workaround. There's no way my 2x4k HDR monitors at 60Hz are fine with my GPU's VRAM at 405MHz but need it to be pegged at 9500MHz if they're set at 144Hz. I'll just have to set my monitors to 60Hz when I'm just working or browsing to lower power consumption in about 60%, I guess.

[Glenwing]

On 6/3/2024 at 8:31 AM, Vasllo said:

If anyone has this issue in the future, here's the info I collected about it:

 

Gainward told me it's expected behavior on high refresh monitors. This sounds like total BS to me, it's pretty clear it's just shitty drivers from Nvidia that just do this as a workaround. There's no way my 2x4k HDR monitors at 60Hz are fine with my GPU's VRAM at 405MHz but need it to be pegged at 9500MHz if they're set at 144Hz. I'll just have to set my monitors to 60Hz when I'm just working or browsing to lower power consumption in about 60%, I guess.

This can happen if the vertical blanking interval is too short because there isn't enough time between frames to retrain the VRAM to a different timing. The vertical blanking interval may be reduced by the monitor manufacturer to achieve high refresh rates when running close to the maximum bit rate of the video connection.

 

The first revision of the LG 27GL850 for example only supported HBR2 DisplayPort link speed which normally is only good enough for 1440p 120 Hz with 10 bpc RGB color when using standard timings, but LG used non-standard very reduced video timings (blanking intervals) to barely squeeze 144 Hz at 10 bpc color depth into an HBR2 link. Which worked, but also gives you this issue of graphics cards not downclocking memory at idle. The later silent revision added support for HBR3 and got rid of the problem.

 

When using DSC (which would be needed for 4K 144 Hz if you are using DisplayPort)  all timings are also reduced proportional to the compression ratio, so if a monitor manufacturer is not careful to account for this they may end up with timings that are shorter than they expect. They may just use some standard blanking interval that they've used in the past which worked fine and so they stick with it, but actually isn't enough when reduced by DSC.

 

You can try increasing the vertical blanking interval manually using CRU: https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

 

Select the correct monitor in the dropdown at the top and then find the 4K 144 Hz profile (it will be inside an extension block in the bottom area) and increase the vertical back porch, maybe like 50 at a time. Press OK on everything and restart the graphics driver with the restart64.exe in the CRU folder to test each setting.

[Vasllo]

On 6/5/2024 at 12:04 PM, Glenwing said:

This can happen if the vertical blanking interval is too short because there isn't enough time between frames to retrain the VRAM to a different timing. The vertical blanking interval may be reduced by the monitor manufacturer to achieve high refresh rates when running close to the maximum bit rate of the video connection.

 

The first revision of the LG 27GL850 for example only supported HBR2 DisplayPort link speed for example, which normally is only good enough for 1440p 120 Hz with 10 bpc RGB color when using standard timings, but LG used non-standard very reduced video timings (blanking intervals) to barely squeeze 144 Hz at 10 bpc color depth into an HBR2 link. Which worked, but also gives you this issue of graphics cards not downclocking memory at idle. The later silent revision added support for HBR3 and got rid of the problem.

 

When using DSC (which would be needed for 4K 144 Hz if you are using DisplayPort)  all timings are also reduced proportional to the compression ratio, so if a monitor manufacturer is not careful to account for this they may end up with timings that are shorter than they expect. They may just use some standard blanking interval that they've used in the past which worked fine and so they stick with it, but actually isn't enough when reduced by DSC.

 

You can try increasing the vertical blanking interval manually using CRU: https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

 

Select the correct monitor in the dropdown at the top and then find the 4K 144 Hz profile (it will be inside an extension block in the bottom area) and increase the vertical back porch, maybe like 50 at a time. Press OK on everything and restart the graphics driver with the restart64.exe in the CRU folder to test each setting.

Thanks a lot! I had found some info here and there about this, but I didn't feel like messing with it with little info, but now I'll definitely try this out. I would even take 120Hz if it solved this, I'll give it a try with CRU.

Seriously, thanks and have an awesome week!

[Vasllo]

On 6/5/2024 at 12:04 PM, Glenwing said:

This can happen if the vertical blanking interval is too short because there isn't enough time between frames to retrain the VRAM to a different timing. The vertical blanking interval may be reduced by the monitor manufacturer to achieve high refresh rates when running close to the maximum bit rate of the video connection.

 

The first revision of the LG 27GL850 for example only supported HBR2 DisplayPort link speed which normally is only good enough for 1440p 120 Hz with 10 bpc RGB color when using standard timings, but LG used non-standard very reduced video timings (blanking intervals) to barely squeeze 144 Hz at 10 bpc color depth into an HBR2 link. Which worked, but also gives you this issue of graphics cards not downclocking memory at idle. The later silent revision added support for HBR3 and got rid of the problem.

 

When using DSC (which would be needed for 4K 144 Hz if you are using DisplayPort)  all timings are also reduced proportional to the compression ratio, so if a monitor manufacturer is not careful to account for this they may end up with timings that are shorter than they expect. They may just use some standard blanking interval that they've used in the past which worked fine and so they stick with it, but actually isn't enough when reduced by DSC.

 

You can try increasing the vertical blanking interval manually using CRU: https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

 

Select the correct monitor in the dropdown at the top and then find the 4K 144 Hz profile (it will be inside an extension block in the bottom area) and increase the vertical back porch, maybe like 50 at a time. Press OK on everything and restart the graphics driver with the restart64.exe in the CRU folder to test each setting.

Well, I tried, and it wasn't fun, nor seemed to be enough. It seems like each display increased memory resources needs, because I can run just one at 144Hz fine, but two won't work.

 

After some exploring, I found the profile in Extension blocks > DisplayID 1.3 > Detailed resolutions. There's only 144Hz there and I managed to make the memory downclock to 5000MHz instead of the 9500MHz, but only with one monitor at 144Hz and the other at 60Hz while pushing the 144Hz one to 112 lines on the vertical back porch. If I pushed more the vertical back porch, I lost signal and I spent quite some time fixing this multiple times.

 

Then I tried creating a new detailed resolution for 120Hz to see if I could downclock the memory while running both at 120Hz, but I stupidly applied it to both at once, broke the driver and couldn't get video past the UEFI and had to use safe mode (which was quite broken, and I couldn't unzip DDU through context menu) to use DDU and reinstall the drivers, because I couldn't get video past POST.

 

It was, an experience... But I guess I give up and will let it rip.

 

[Glenwing]

3 hours ago, Vasllo said:

Well, I tried, and it wasn't fun, nor seemed to be enough. It seems like each display increased memory resources needs, because I can run just one at 144Hz fine, but two won't work.

 

After some exploring, I found the profile in Extension blocks > DisplayID 1.3 > Detailed resolutions. There's only 144Hz there and I managed to make the memory downclock to 5000MHz instead of the 9500MHz, but only with one monitor at 144Hz and the other at 60Hz while pushing the 144Hz one to 112 lines on the vertical back porch. If I pushed more the vertical back porch, I lost signal and I spent quite some time fixing this multiple times.

 

Then I tried creating a new detailed resolution for 120Hz to see if I could downclock the memory while running both at 120Hz, but I stupidly applied it to both at once, broke the driver and couldn't get video past the UEFI and had to use safe mode (which was quite broken, and I couldn't unzip DDU through context menu) to use DDU and reinstall the drivers, because I couldn't get video past POST.

 

It was, an experience... But I guess I give up and will let it rip.

FYI (for future Google searches) running the reset-all.exe in the CRU folder should get rid of any modifications you made in CRU.