What makes an editing PC fast - good video card (gpu) or the processor (cpu)?

I want to upgrade my computer. I am running a 3gen i7 processor a geforce 1050.

I find that lightroom is slow when I scroll through photos in develop mode? Faster rendering in develop mode would make my editing faster...

What should I upgrade? Processor or the video card? I would like to hear opinions from photographers or videographers who have done the upgrade... I already upgraded the hard drive to ssd.

Thanks a bunch!

Beside a proper processor supported by sufficient RAM, scratch disk space,
wisely developed workflow, and adequate GPU, the app must be able to fol-
low your ambitions.

In this, Lr is notoriously not recognised to be top performing. I don't use it sin-
ce a long time — or anything adobe for that matter — more modern tools are
way better performing, less heavy and more flexible.

Yes, you not only need a fast processor chip and video card, but lots of RAM, good stable hard drives, and fast software. the best hard drives mow being the solid state drives. It's a never ending battle, with larger file sizes and the desire to process them more and faster, additional space and processing speed becomes necessary. It's usually bet to completely replace the computer every few years to get the benefits of this than replacing pieces of an older computer, but get one with the most RAM, CPU speed, video capability, and hard drive space that you can. Although a big ticket item all at once, it will save money and result in satisfying your desire for speed and capacity better. Putting a supercharged V-8 engine in a Model A Ford didn't work very well either.

Charley

Yes.

Not to discount the RAM you need

haring wrote: I want to upgrade my computer. I am running a 3gen i7 processor a geforce 1050.
I find that lightroom is slow when I scroll through photos in develop mode? Faster rendering in develop mode would make my editing faster...What should I upgrade? Processor or the video card? I would like to hear opinions from photographers or videographers who have done the upgrade... I already upgraded the hard drive to ssd.
Thanks a bunch!

Your whole computer. Moving to an SSD would help speed up your old computer from a spinning disk would be a noticeable difference in transferring data to at 600 megabytes per second. The problem is todays motherboards use nvme and depending on PCIe lanes you get 3500 megabytes per second or gen 4 up to 7000 MB per sec. The bus speed on the mother board is so much faster. 3rd gen I7 use DMI2.0  that has been replaced by DMI 3.0,  DMI 4.0, DMIx8. That is bus memory bus speed how fast data travels between memory and cpu.
Add to the the speed increase in the memory itself and other motherboard speed enhancements make your user experience faster and better.
Leave this computer as it is for someone else in your family, build yourself a new computer or buy a new laptop.
Buy a new laptop computer during black friday/Christmas. Every year including this one they have a 16.5 gaming laptop with a Ryzen 4800/5800 8 core 16 thread with a faster video card than you have for $899 that will be similar or slightly faster than the M1's in productivity, photo and video editing , but not the M1pro or Max. Hook it to a nice monitor and you have a fast computer. Those laptops right now are $1299 but at Christmas are $899 
I know that is not what you want to hear but there it is.
I am not a mac guy but the M1 mac mini at best buy is $899, It will run photoshop at similar speeds to the gaming laptop, it is $899. If you going to edit video, either the laptop or mac mini need 16gb of ram. The laptop is upgradable You have to buy the Mac with 16gb of ram at $1299

Nikon Shooter wrote: Beside a proper processor supported by sufficient RAM, scratch disk space,
wisely developed workflow, and adequate GPU, the app must be able to fol-
low your ambitions.

In this, Lr is notoriously not recognised to be top performing. I don't use it sin-
ce a long time — or anything adobe for that matter — more modern tools are
way better performing, less heavy and more flexible.

When was the last time you used LR or photoshop?

haring wrote: What should I upgrade? Processor or the video card? I would like to hear opinions from photographers or videographers who have done the upgrade... I already upgraded the hard drive to ssd.
Thanks a bunch!

One more thing. If you are still going to upgrade one or the other, go for the CPU.
This shows GPU acceleration is hit and miss and could cause more problems than it is worth.

photographylife.com/gpu-acceleration-in-lightroom

Quote from article
As I have pointed out earlier, GPU acceleration can introduce problems in Lightroom. Below is the full list of issues I have come
across:

• Extremely sluggish brush performance
• Image previews disappearing and showing as black or some other color
• Black image when zooming in or panning the image
• Slow performance when jumping between images
• Overall reduced Lightroom performance

If you notice any of the above issues, try disabling GPU acceleration and
see if it improves Lightroom performance and its stability. Since GPU
acceleration is a hit and miss for a lot of Lightroom users out there,
you should experiment and see whether it brings you any performance
improvements or not.

r1ch wrote:

haring wrote: What should I upgrade? Processor or the video card? I would like to hear opinions from photographers or videographers who have done the upgrade... I already upgraded the hard drive to ssd.
Thanks a bunch!

One more thing. If you are still going to upgrade one or the other, go for the CPU.
This shows GPU acceleration is hit and miss and could cause more problems than it is worth.

photographylife.com/gpu-acceleration-in-lightroom

Quote from article
As I have pointed out earlier, GPU acceleration can introduce problems in Lightroom. Below is the full list of issues I have come
across:

• Extremely sluggish brush performance
• Image previews disappearing and showing as black or some other color
• Black image when zooming in or panning the image
• Slow performance when jumping between images
• Overall reduced Lightroom performance

If you notice any of the above issues, try disabling GPU acceleration and
see if it improves Lightroom performance and its stability. Since GPU
acceleration is a hit and miss for a lot of Lightroom users out there,
you should experiment and see whether it brings you any performance
improvements or not.

Honestly RAM > GPU for lightroom.

Scotty wrote: When was the last time you used LR or photoshop?

It was last week, not all my students want to leave their familiar
software so the remote online sessions are done with those.

Nikon Shooter wrote:

Scotty wrote: When was the last time you used LR or photoshop?

It was last week, not all my students want to leave their familiar
software so the remote online sessions are done with those.

You teach workshops?

Only 6 workshops per years— I even want to go slower as I am
hoping to pre-retire — but mentoring and tutoring are still active.

Nikon Shooter wrote: Only 6 workshops per years— I even want to go slower as I am
hoping to pre-retire — but mentoring and tutoring are still active.

Nice! Retirement sounds good. You'll end up still doing it probably though.

Nice you say, Scotty?

Horrible I answer. My sons want to take over… good for them but that
means that I will have to move aside… very difficult. I hate the idea.

Nikon Shooter wrote: Nice you say, Scotty?

Horrible I answer. My sons want to take over… good for them but that
means that I will have to move aside… very difficult. I hate the idea.

Pass the torch.