What's important depends also on the program, version and build you will use.
Newer versions have newer and faster options with stronger processors and newer videocards than the older versions.

Thanks both for your input.

Dexcon, thanks for the link but Grazie's system specs are way over my budget limitations.

If it's just 1080p without plans to go to 4K you won't need anything outrageous.

For 1080p, my Ryzen 2200G (with 16GB RAM and an AMD Radeon RX570) handles things fine. That said, once you start adding a load of grades and/or effects it can slow down... Something more Ryzen 5 or recent Intel i5 should be more than adequate to keep 1080p smooth with effects or grades added I would think (although others may correct me on this).

@j-v and @Dexcon are both right about making a decision based on the particular version - 15 and 16 can use GPU acceleration for rendering out a video and the various reveals for 17 suggest that it will have GPU timeline playback acceleration but until it's released we won't know if it favours NVidia (CUDA and OpenCL) or AMD (OpenCL only) I guess!

To be fair, you could probably keep your existing system and upgrade the RAM to 16GB, upgrade the graphics card to an Nvidia 10xx series or Radeon RX5xx (70 or above) or Radeon VEGA (56 or 64) and put in an SSD (if you're not already using one) and see some good performance with the more recent Vegas Pro versions - you'd get NVENC encoding with the Nvidia for H264 (AVC) and H265 (HVEC) or AMD-VCE encoding with the Radeons for the same codecs. In VP17 this would hopefully extend to timeline acceleration on both cards but if Magix have implemented CUDA timeline acceleration only then it would be NVidia exclusive.

Having gone through all that - what is your budget as that will determine what is ideal for you?

@Jack S

If you've been happy with your Dell XPS 8700 over the years (as I have been), you might want to check out Dell's current XPS offerings on your country's Dell website. I've just had a look at Dell Australia, and the top XPS here is now an 8 core i9, 16GB RAM, Nvidia 8GB 2060 GPU, 512GB M.2 drive with a TB HD. If you're not dealing with 4K, this should be more than sufficient I would think.

I've noted over the years that Dell's offers tend to change in configuration every 2 weeks or so. It might be like above now, but the next offer might 16GB GPU but with a 256GB M.2 drive.

And Dell often have discounts as well - 25% off at the moment here in AU.

EDIT: the suggestion to update by @jrb101 could well be your most cost-effective solution for the time being.

@j-v and @Dexcon are both right about making a decision based on the particular version - 15 and 16 can use GPU acceleration for rendering out a video and the various reveals for 17 suggest that it will have GPU timeline playback acceleration but until it's released we won't know if it favours NVidia (CUDA and OpenCL) or AMD (OpenCL only) I guess!

Nvidia Cuda does not exist anymore.
CUDA was available in VPro 14 and in VVpro 15 only at the Sony AVC codec and that faulty option existed only in the older NVidia cards.
The new Nvidia cards and VPro 16 have only the NV Encoder (NVENC) of Nvidia.

I thought NVENC is for encoding, CUDA is for computing.

So, for timeline acceleration Cuda or OpenCL is necessary. Am I wrong here?

I thought NVENC is for encoding, CUDA is for computing.

So, for timeline acceleration Cuda or OpenCL is necessary. Am I wrong here?

That's right.

@j-v - yep NVENC (AMD's VCE) is used for encoding, but I'm fairly certain that any timeline playback acceleration would be handled by CUDA (or OpenCL) as it is in Resolve or Premiere Pro. I wasn't referring to CUDA encoding as you're right that NVENC has replaced this function.

I don't know what timeline playback acceleration is and does, maybe you have to ask someone else or the developpers.
The timeline play in Vegas is done by the processor and the hardware acceleration is used for previewing most effects added to the project and it is done by my Nvidia GPU

@jrb101 FYI, In Vegas timeline accel. = Open CL; never been CUDA. Was a time long past where Mainconcept encoder used CUDA. No longer.

V17 may add other timeline GPU accel. but very much doubt that will include CUDA as it's ancient.

There's a benchmarking thread in these forums that a couple users have done a great job of creating, it contains results from our machines and how well they performed, and you can see how a wide variety of hardware configs does by looking in that thread at what we used and how well it scored.

https://www.vegascreativesoftware.info/us/forum/benchmarking--116285/

@jrb101 FYI, In Vegas timeline accel. = Open CL; never been CUDA. Was a time long past where Mainconcept encoder used CUDA. No longer.

V17 may add other timeline GPU accel. but very much doubt that will include CUDA as it's ancient.

CUDA isn't ancient - it's at v10.1 at the moment (2019 release) but I'll concede that using actual CUDA cores for video encoding like Mainconcept used to is a ancient technology - it's now done by NVENC on a specific chip on NVidia cards...

But this is all way off-topic so I'm going to stop here and point back to the original question: @Jack S - do you have a budget in mind for an upgrade?

Fair enough.

For OP: Nice time to be building a new system - lots of good choices that will support HD or UHD workflows. I like the look of the new AMD Ryzen chips.

FWIW, I would keep in mind system longevity / upgradability. By going "big" initially, I have kept my 2010 system running for 9 years now, and that has saved me a lot of time & money. The time for an upgrade has definitely arrived now though. :)

I don't know what timeline playback acceleration is and does, maybe you have to ask someone else or the developpers.
The timeline play in Vegas is done by the processor and the hardware acceleration is used for previewing most effects added to the project and it is done by my Nvidia GPU

I've been playing around with that setting recently. My laptop's weak point is it's GPU. I knew this when purchasing it since my intent was I was going to mainly be using it for audio, but more recently have gotten more involved in video projects.

This is my system configuration. Slow Nvidia 940MX GPU.

https://www.userbenchmark.com/UserRun/16876259

What I noticed in my instance, I originally had the Nvidia 940MX GPU selected, and when I had some video fxs loaded on a 1080 project, I was getting some playback preview lag. I turned it to the off position, which I'm assuming would cause Vegas to only use my CPU instead of the GPU and my playback preview lag went away. So I'm guessing, you only want to select the GPU with that setting if you have a higher end GPU?

 I was getting some playback preview lag.

Reason can be weak processor or GPU( only when it is the playback of an added FX) or memory not refreshing quick enough for your project.

 I was getting some playback preview lag.

Reason can be weak processor or GPU( only when it is the playback of an added FX) or memory refreshing quick enough for your project.

I guess that's the part I'm trying to understand more. I was thinking my memory is likely enough, 32GB of DDR4-2400 Crucial Ballistix or are you referring to GPU memory? My GPU is definitely weak. Trying to understand what the "Off" setting position does since that's the setting which gave me the best preview playback without lag when I had FXs applied.

When it is set to use your GPU, Vegas uses it to render the timeline, which includes processing of certain effects added to the timeline. When you have a weak GPU, a stronger CPU may actually do this job faster, which is why you notice the performance increase when you disable your GPU.