Does CRU custom res introduce input lag?

[Grasshopper85]

So, in the past I when I had an RTX 4090 I would use NV_Nodes in windows registry to add any custom resolutions I liked to play PUBG with, specifically 1728x1080.

Now with the RTX 5090, editing NV_Nodes and adding custom resolutions has no effect, so any custom resolutions added there will not be shown in NVCP. Instead we can use CRU. But I am wondering, does CRU add input delay that otherwise would not have been introduced with the NV_Nodes registry edit?

Reason I ask, is after getting the 5090, I can feel a larger input delay in PUBG. And so it feels less desirable to play.

I'm trying to narrow down the reason.

[Hyote]

CRU presets modify timings for the better, so unless something really gets messed up, which is unlikely, then it's always better to use it.
It's also a bit sad to see another post about newer hardware suffer from this issue.

[JimCarry]

So, in the past I when I had an RTX 4090 I would use NV_Nodes in windows registry to add any custom resolutions I liked to play PUBG with, specifically 1728x1080.

Now with the RTX 5090, editing NV_Nodes and adding custom resolutions has no effect, so any custom resolutions added there will not be shown in NVCP. Instead we can use CRU. But I am wondering, does CRU add input delay that otherwise would not have been introduced with the NV_Nodes registry edit?

Reason I ask, is after getting the 5090, I can feel a larger input delay in PUBG. And so it feels less desirable to play.

I'm trying to narrow down the reason.

.

[Grasshopper85]

What do you guys mean by changing timing?

When I use CRU, I only change/add custom resolution 1728x1080. It works in my games.

Secondly, why do you guys perform scaling on display? When I had my RTX 4090, I felt an instant difference when I used scaling on GPU over Display. Scaling gpu felt more instant for me back then.

Sadly it seems we can not chose scaling on GPU with an RTX 5090 anymore, only scaling on display is available for rtx 5090 owners, I believe. Another downside. *sigh*

[JimCarry]

What do you guys mean by changing timing?

When I use CRU, I only change/add custom resolution 1728x1080. It works in my games.

Secondly, why do you guys perform scaling on display? When I had my RTX 4090, I felt an instant difference when I used scaling on GPU over Display. Scaling gpu felt more instant for me back then.

Sadly it seems we can not chose scaling on GPU with an RTX 5090 anymore, only scaling on display is available for rtx 5090 owners, I believe. Another downside. *sigh*

.

[daemonjax]

I've been using CRU for years and manually entering values, and no, it doesn't "cause" anything unexpected to happen.

EDIT: Ok, exactly 1 caveat to the above (besides the obvious if you use values your lcd can't handle, but that should present as a blurry image if you go only slightly outside the range):

CRU's reported "actual" refresh rate is often incorrect due to the differences in precision/rounding it does and what windows actually does. So if you're trying to dial in a specific refresh rate, you have to double-check that it's what windows actually sees it as, because what windows actually sees it as is the only thing that really matters -- not what CRU shows as the "actual" in it's UI. You play with the back porch to get what you want (and maybe switch between 3 or 4 front porch). If it's not right, frame limiters might not work as expected... you framecap @ 60hz but the panel is actually at 60.001, you may be starving the buffers in the render queue when you didn't mean to. Or adaptive vsync might not work at all with your frame limiter on (I suppose this would be the most glaring example)... same as previous example, but with adaptive vsync enabled it will _never_ actually engage the sync, you'll always get tearing bc you're _always_ below the for-real-as-windows-sees-it actual 60.001hz. Why would someone run adaptive vsync + a framelimiter at the same time? I dunno, game engines are weird sometimes. You do what you gotta do. I've done it.

EDIT2: And looking at your screenshot, be aware that front porch should pretty much always be 3 or 4 lines (vertical).

[JimCarry]

I've been using CRU for years and manually entering values, and no, it doesn't "cause" anything unexpected to happen.

EDIT: Ok, exactly 1 caveat to the above (besides the obvious if you use values your lcd can't handle, but that should present as a blurry image if you go only slightly outside the range):

CRU's reported "actual" refresh rate is often incorrect due to the differences in precision/rounding it does and what windows actually does. So if you're trying to dial in a specific refresh rate, you have to double-check that it's what windows actually sees it as, because what windows actually sees it as is the only thing that really matters -- not what CRU shows as the "actual" in it's UI. You play with the back porch to get what you want (and maybe switch between 3 or 4 front porch).

EDIT2: And looking at your screenshot, be aware that front porch should pretty much always be 3 or 4 lines (vertical).

so did i do it now ?

[daemonjax]

so did i do it now ?

I'd expect it to "work" in the general sense... but if you're trying to actually get it to run at _exactly_ 240.000hz, you have to double-check to see if that's actually what windows sees. check in Settings>Display>Advanced Display Settings>Refresh Rate... it might say something NOT 240.000hz. If it's NOT 240.000hz there, then play with the backporch -- try slightly different backporches that both CRU _and_ Windows also sees as 240.000. If you can't seem find the right value for the backporch, then try changing the front porch from 3 to 4 or vice versa.

And why a custom res of 640x480@240hz? That sounds extremely niche to me. I assume you have a good reason, just curious.

[JimCarry]

so did i do it now ?

I'd expect it to "work" in the general sense... but if you're trying to actually get it to run at _exactly_ 240.000hz, you have to double-check to see if that's actually what windows sees. check in Settings>Display>Advanced Display Settings>Refresh Rate... it might say something NOT 240.000hz. If it's NOT 240.000hz there, then play with the backporch -- try slightly different backporches that both CRU _and_ Windows also sees as 240.000. If you can't seem find it then try changing the front porch from 3 to 4 or vice versa.

[JimCarry]

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