additional render and constructing machine for mainly Terragen

[Dune]

I'm considering a new machine that will be used to build 3D stuff, compile landscapes in Terragen, and render. No gaming. 
I now have a Ryzen 9 5900X, but there are better ones today. My GPU (GTX 1080 Ti) also needs to be a better one, as working in a pretty loaded TG preview screen is sometimes sluggish, and I get occasional complete computer crashes when doing something too fast. 
So I can choose between Threadrippers and Ryzen 9 CPU's, and different NVidia RTX GPU's, of course with plenty DDR4 (or 5?) RAM, a good MB, etc. Some things may be overkill (also moneywise), so I wonder what you guys would recommend, taking into account future GPU rendering as well.

[gao_jian11]

Dune，Updating the equipment is always exciting. I use threadrippers2990, which renders very fast, but the main frequency is a bit low. TG has very high requirements for the main frequency when creating scenes. The graphics card is changing too frequently. I don't recommend buying the latest one as it is expensive and will soon be replaced by a newer model. The GPU rendering by TG has to wait for a few years until better GPUs are available. At that time, there will be better GPUs on the market.

[gao_jian11]

Additionally, I remember that the maximum number of cores supported by TG is 32 and the maximum number of threads is 64. Beyond these limits, it won't work. I wonder if this is still the case now.

[Dune]

Thanks for your input, gao jian. There are indeed so many things to consider that it sometimes overwhelms me, like the frequency you mention, the number of cores/threads and whether they can all be utilized, I need to dive into CUDA (are they important?), etc. 
You may well be right about a GPU, but I'm pretty anxious to purchase something this year, as I don't know how my income will be next year (tax deduction considerations and all). It doesn't need to be an ultimate machine, as that will keep changing over the years indeed, but a good price-performance average at this moment. A 10% speed gain for thousands of euro's isn't what I'm after. So it won't be the 32GB GPU's that are available.
Thnks for your points to keep in mind!
 

[digitalguru]

Additionally, I remember that the maximum number of cores supported by TG is 32 and the maximum number of threads is 64. Beyond these limits, it won't work. I wonder if this is still the case now.

That limit is gone apparently in Terragen 4.8.23 - from the release notes:

We've removed a hard-coded maximum of 64 threads per render. This allows utilization of more than 64 cores/hyperthreads on Windows 11, Windows Server 2022, Linux, and Macs with more than 64 cores. Older versions of Windows may not benefit.

Agree with gao_jian11 on the GPU front if you're mainly working with Terragen, but then again who knows what will happen with TG and GPU rendering? - TG 5 has been in development for years now - maybe worth asking Matt if future versions will use GPU more (if he'll tell you )

[Kevin Kipper]

I built a Threadripper workstation a few years ago primarily to render in Terragen and in that respect it's great.  It's a Windows 10 system which means that the only way to utilize the full 64 cores (128 threads) at once during a Terragen render is to launch two instances of Terragen.  That's fine for an animated sequence because one instance of Terragen is rendering the odd numbered frames while the other instance is rendering the even number of frames.  Generally speaking using this workflow I end up with two rendered frames in the "time" it takes to render one.  For still images I can render on an instance just dedicated to rendering, while working in another Terragen scene or another application all together.   If you can build a Threadripper using Windows 11 this limitation should no longer apply. 

I've not tried to render via render management applications like Deadline, or tried to render a large image in tiles and then have it stitched back together.

One thing I've noticed is that the user interaction in Terragen on my 13+ year old Intel 7 system with a GTX670 graphics card is much smoother and faster than on my Threadripper system, even though the new system has 4 times the memory and a 3080ti graphics card.  Also, although I haven't tried this yet, Matt suggested I try reducing the number of cores per Terragen scene from the default 32 to see if it improves the perceived performance.

Overall I'm happy with the Threadripper.  I render much larger images at higher quality than previously.

[Dune]

Thank you both for chiming in! Good information to take into account, copied all.

Strange that this older GPU works less smoothly than the newer one, as that's one of the reasons I'd invest in a faster card. And being able to work in 3D and render a large scene at the same time, because I'm very anxious to do so now, afraid of crashes and having to start a render all over again.