quchempedia@home is one of the project that runs on CPU only.
In the past, I've ran a Xeon server, later on, regular Core i5 CPUs and Pentium G processors.
Now I plan on running a newly purchased 'Ryzen 9 3900X' system, dedicated to them (at least the CPU part).
 
12 cores, 24 threads, 4,4Ghz, paired with 32GB of 3200Mhz DDR4 ram.
Aircooled!
It doesn't support AVX512 yet, but not a lot of projects actually use this feature (none), and few use AVX2.

The motherboard accepts 3 GPUs at a 8x/4x/4x PCIE 3.0 or PCIE 4.0 configuration, or possibly 5 to 6 GPUs if PCIE x1 slots are utilized; so it's future proof.
It'll greatly speed up my contributions to them, all while keeping electric load and monthly electric cost down.
The server will go online this week!
 
Super stoked about it!
 
The reason why I went with the 3900x, is price/performance.
The 3800x runs at the same TDP, but benchmarks ran it at 30% slower. The price is also around 35% lower. So they're pretty even in terms of dollar per performance.
The 3950x runs also at the same TDP, 10% faster according to benchmarks, but costs almost double the price (more than double, if you include a cooling solution); and it wasn't worth it for me.
The 3960x (threadripper) is another $1000 on top of that. While having double the cores, the price of it becomes slightly too high.
Although they're great for crunching!

ProDigit
quchempedia@home is one of the project that runs on CPU only.
In the past, I've ran a Xeon server, later on, regular Core i5 CPUs and Pentium G processors.
Now I plan on running a newly purchased 'Ryzen 9 3900X' system, dedicated to them (at least the CPU part).
 
12 cores, 24 threads, 4,4Ghz, paired with 32GB of 3200Mhz DDR4 ram.
Aircooled!
It doesn't support AVX512 yet, but not a lot of projects actually use this feature (none), and few use AVX2.

The motherboard accepts 3 GPUs at a 8x/4x/4x PCIE 3.0 or PCIE 4.0 configuration, or possibly 5 to 6 GPUs if PCIE x1 slots are utilized; so it's future proof.
It'll greatly speed up my contributions to them, all while keeping electric load and monthly electric cost down.
The server will go online this week!
 
Super stoked about it!
 
The reason why I went with the 3900x, is price/performance.
The 3800x runs at the same TDP, but benchmarks ran it at 30% slower. The price is also around 35% lower. So they're pretty even in terms of dollar per performance.
The 3950x runs also at the same TDP, 10% faster according to benchmarks, but costs almost double the price (more than double, if you include a cooling solution); and it wasn't worth it for me.
The 3960x (threadripper) is another $1000 on top of that. While having double the cores, the price of it becomes slightly too high.
Although they're great for crunching!

I would not say no projects use AVX512
Primegrid LLR subprojects use AVX512 and it makes a huge difference, so much faster.