computer, lots of lag...need a little help, please!

Hey everyone, my name is Ross, and I edit for a YouTube channel. I'm hoping to get some help. Ive been editing for years, but nothing as advanced as DVR 19 Studio, but ive done my fair share of research in the last 2 weeks to know some of the settings that needed to be changed (that info is below). I've watched 50 videos and perused this forum for answers, made some changes, and still getting a considerable amount of lag during playback in the edit screen, and ive only dropped a-roll into the timeline with a few transitions, havent even started adding b-roll tracks. btw, all the footage is H264 from a DJI pocket 3.

Let me start with my laptop:
NVIDIA RTX 4070, Intel 14th Gen i9-14900HX, 64 GB DDR5-5600, 4 TB Gen4 SSD (close to 2.75TB are free), 16" ROG Nebula 16:10 QHD 240Hz, Win 11 Pro,

ive also gone into the graphics settings on the laptop, added davinci to the list and picked the RTX 4070 as GPU preference.

im also running 4 screens, if that makes a difference. 1 on the HDMI out (30hz), the other 2 split from a USBC output to an HDMI splitter (59.94hz), and of course the laptop monitor (240hz)

i see a NVDisplay.container.exe file in my graphics settings, havent touched that one yet, but its using the "power saving intenl uhd graphics" right now. (should that be set to NVIDIA?)

Here are the changes Ive made in the software:
-i record everything in 4k 59.94, timeline resolution is set to 3840 x 2160 ultra hd (for 3840x2160 processing).
-playback frame rate 59.94
-video monitoring (not sure if this matters?) i set to 1280 x720 hd 720p, in thinking because i dont do a lot of color grading or fusion stuff besides some spline curves) a lower video resolution would help.
-proxy media resolution: quarter, proxy media format DNxHR LB (had it set on SQ prior)
-render cache is set to smart, that did help a little with transitions (i see the blue line above the area that is cached). should this be set to user?

memory and gpu settings: system memory 63.6 GB, both resolve and fusion memory set to max (47.7 and 35.8 respectively)
-GPU processing mode set to auto, then CUDA, didnt see much of a difference either way.
-neural engine opt on NVIDIA is checked
-NVIDIA GeForce RTX 4070 is set for main display (auto is checked off), and the INTEL UHD Graphix is grayed out
-i dont remember where the setting was but it has something to do with stopping the time line from contuning if it sees a drop in frame rate, which is turned off.

I thought this pc would handle this with ease... Please help, what am I missing? i am using the monitor that runs at 30 HZ for editing, since it is the largest, but can delete if thats my problem. Any help for this NOOB would be appreciated.

I'm not a computer guy, part of the reason i bought a laptop that would just be overkill for what i need. but if there are computer or software settings Im missing, i can find those. Thank you in advance!

just a heads up, i removed 2 monitors, despite the system being able to display 4, everything seems to be running much better with only 1 external monitor. however, if there is anything you want to add to my original post above, please feel free. i have learned about 1% of DVR so far. Thanks everyone!

I can't speak about the hardware stuff, but some things to consider. Since resolve is resolution agnostic, and you said you mostly do editing, you could easily drop timeline resolution to 1080p, do your editing and go back up to UltraHD when you are done. If you set it up corectely, there should be no loss in final quality of output, only faster editing. This could also be done with any motion graphics you might be using. Auto resolution mode and scaling of graphics means, you can have any motion graphics scale up and down with all the elements as you change timeline resolution, and if you work with 4K clips, and some motion graphics etc, its easier to just use 1080p timeline for editing, where you need speed and reasonable quality, and later just change timeline resolution to whatever your output is. If you do color grading it depends on what you are monitoring and do you do any precision masking.

When changing resolution of the timeline, if you want to also transform, pan and zoom clips, look into chapter about mismatch resolution section in the reference manual to understand dos and don's, but it should be pretty easy to get into good habits.

Another thing to consider is Timeline Playback Resolution , available from the top menu (playback), which is just resolve dropping resolution on the GPU with the signal that goes to the viewer (not sure how it works for multiple monitors), so you get more pixelated draft mode in the viewer, but faster playback, and if you need to just focus on timing not quality, this is a good way to get boost in performance, with no need to make duplicates of the files or wait for rendering. Its all done on the fly on the GPU. And its easy to turn on or off at any point. You can choose between full quality, half and quarter. Add keyboard shortcuts and you can turn it on and off as you work and need speed or quality.

With those two things, I would think you should be mostly set to do editing. But if you want more on optimization, there is a pretty good video overview of various ways things could be optimized, not sure if you have seen it.

Fusion is a special case, there are tones of things to do there for optimization, so if you end up working there and want more, ask here and I'll try to expand on it, but if you are not heavy fusion user and mostly are focused on editing, I think that is enough.

Personally I think the first two things I mentioned: changing timeline resolution and timeline playback resolution are two modes that are criminally underrated but are quite powerful in resolve. For more info on how resolution works in resolve, I would suggest you take a look at reference manual, available from help menu. It will explain any question marks, and its pretty good on the caching chapter as well.

One detail does stand out in your report (besides driving too many monitors, as you discovered).

In the past -- haven't tested it in years -- a monitoring resolution which differed from the timeline resolution was a source of poor performance.

As advised above, there's a better way. Drop the timeline resolution to HD (or even 720p) and monitor at that same resolution. If you *must* deliver at UHD, change the timeline to UHD before delivery, with the caveats also noted above.

In the past -- haven't tested it in years -- a monitoring resolution which differed from the timeline resolution was a source of poor performance.

this has been fixed....

I will try to work with only one monitor for now and assess the performance.

One detail does stand out in your report (besides driving too many monitors, as you discovered).

In the past -- haven't tested it in years -- a monitoring resolution which differed from the timeline resolution was a source of poor performance.

As advised above, there's a better way. Drop the timeline resolution to HD (or even 720p) and monitor at that same resolution. If you *must* deliver at UHD, change the timeline to UHD before delivery, with the caveats also noted above.

so i can just drop the timeline resolution in the project settings to 1920-1080 for smoother editing, and then change that back to ultra hd before delivering? makes sense, thanks