Best Server To Run Roon Core

+2 on the SGC STi5. I run one without any internal storage, keep my library on a Synology NAS, both outside the listening room. I use a Sonore opticalRendu as the renderer/network player taking the signal via ethernet and feeding my DAC. 
At $1K the Sonictransporter is basically a plug 'n play Roon core priced between an Intel NUC DIY build and the costlier Roon Nucleus(+). 
Since you asked, the rest of the system details are here: https://systems.audiogon.com/systems/133. Cheers,
Spencer

Everyone, thanks.  This is is all really good info.  For now, I would just try to run to one end point and expand in the future if I was to adopt roon.

I read today that in some cases Roon Core can be installed on Synology Nas as well. I assume this is NAS model specific and there are processing requirements that need to be met.

I believe you will find the NAS may be difficult to adequately spec to run Roon well. It will also depend on the size of your current digital library as to the level of server you will need to meet basic quality requirements for Roon.  Highly second a previous recommendation to look at Wolf Audio servers.  US company and they provide excellent information as well as after the sale support.  Reach out to Wolf Audio and speak with the designer/builder Joe Parvey about the different levels of servers available that could be custom built for you. 

I watched John Darko’s recent video on how to build an Intel NUC 

https://youtu.be/ZVm_tCoxqyg and thought that would be a nice quarantine project. So for $762.40 I ordered an i7 NUC, 32GB (16GB x2) RAM and a 250 GB SSD. It was simple to assemble. Updating the Bios wasn’t bad and loading Roon ROCK was a breeze. The kind of NUC I ordered has an external SMPS brick. Plus you can adjust how and when the fan operates in the Bios. But in my testing it doesn’t run much. So I tested it against my Innuos Zenith Mk3. The NUCs background is black. Roon Remote runs snappy and doesn’t crash. All my streaming runs great. I have a number of Roon endpoints on my network. Everything runs great. Soon I will attach my Innuos Phoenix after one of my UltraRendus and see. But I have been thrilled with the NUCs performance so far. I sold my Innuos server. I replaced a $5000 retail unit (2TB version) with an overbuilt $762.40 NUC! Now I have some $ to go out and get a good tube Integrated! Highly recommended. 

The new Mac Mini (new M1 chipset) is dead silent, inexpensive, and if you configure it properly, it is a fantastic option.  I’m running it on treated power with an Oyaide C7 for the mains.  Get a quality network cable, shut off Bluetooth and WiFi, and you’re fine running USB directly from the core.  I use an Intona USB 3.0 isolator, but found that I was almost as satisfied with the sound without using it.  I have built multiple Roon cores, built endpoints with custom LPS and DC cables, and this works as well if not better.  You can also optically isolate the server with a pair of media converters.  I’ve been using a certain type of stone for mechanical isolation, perhaps that helps as well.  Even if the core is running in Rosetta for now, I like what I hear.