The Dell "workstations" (their commercial business workstation line) are just about all Intel.  A couple of the Inspiron gaming desktops are Ryzen and a couple low end (entry) systems are AMD, the rest Intel.
 

fireberd
The Dell "workstations" (their commercial business workstation line) are just about all Intel.  A couple of the Inspiron gaming desktops are Ryzen and a couple low end (entry) systems are AMD, the rest Intel.
 

Hi Jack, with all due respect, and I mean that most sincerely, to clarify my point, tests and technical specifications indicate that AMD chips are most effect for the workstation as opposed to Intel's which are more effective in the gaming sector.  That said, it's no surprise that a company like Dell would use the more commonly known Intel in their workstations, not that Intel chips would be ineffective in a workstation.  Speaking from an technical perspective, of which I have no such expertise in (hence my screen name), AMD is and would be the preferred system.  As you may note that many high-end workstation vendors and builders would utilize AMD over i7s and i9s with the exception of the more expensive Xeons.
 
I've read Jim's posts on the subject and if I would be so bold to sparse his words, his point would be a matter of implementation as opposed to the technical benefit and effectiveness of AMD chips in the workstation environment not to mention that ThreadRippers are not even considered these comparisons.

My posts discussing Ryzen are coming from a DAW user's perspective.
A corporate server is a much different scenario.
Corporate servers are bombarded for many small files.
With a DAW, we're addressing many fewer... but much larger/contiguous files.
With a corporate server, since you're dealing with many small files, cache can make a significant difference.
This is why Xeon CPUs (even with lower clock-speed) are a good choice.
For a DAW, dealing with much fewer large/contiguous files, cache makes much less of a difference. 
 
When choosing a CPU for DAW purposes, it's important to understand some basics:
Not all tasks in a DAW can be multi-threaded (spread across multiple cores).
This is why high clock-speed is paramount.
In a perfect scenario, you want highest clock-speed, the most cores you can afford, and Hyper-threading/SMT (simultaneous multi-threading).
 
If you go AMD, there's no option for Thunderbolt-3 (completely off the table).
 
When Ryzen was first released, supporting hardware (motherboards) were clearly "rushed out the door".
I've discussed this in numerous threads.  
With AMD's Infinity-Fabric architecture, running faster RAM (DDR4/3200) is a significant speed boost.
Finding a motherboard that can run DDR4/3200 rock-solid stable is an epic quest.
Out of all the top-tier motherboards, only one came close. 
After several days, it simply refused to post.  Had to clear the CMOS and reset the BIOS settings.
Note that no over-clocking was implemented.  This is all at stock-speed... trying to run DDR4/3200.
 
If you spend the majority of your time rendering video (which is a heavily multi-threaded task), don't expect to ever need Thunderbolt-3, and aren't concerned with the speed benefit from faster RAM, Ryzen is a good choice.
 
For DAW purposes, the new Intel i9-9900k (socket 1151) is hard to beat (~$540).

• 8 cores
• 16 processing threads
• 5GHz clock-speed (all cores can be locked at 5GHz)
• With quality air-cooler, it runs near dead-silent
• Thunderbolt-3 is an option

 
The (socket 2066) i9-9980xe is one monster of a CPU... best overall performance currently available

• 18 cores
• 36 processing threads
• 4.5GHz clock-speed
• Thunderbolt-3 is an option

Cost is also monstrous ($2000 just for the CPU)
Requires high-end power-supply
Requires high-end cooling (air cooling can't keep temps under control when under heavy loads like rendering video)
 
If going to the expense of ThreadRipper (also requires high-end cooling/power), I'd just go all the way and get the 9980xe.  
 
 
Note that if going ThreadRipper or socket 2066 i9 CPU, the machine isn't going to run as quiet at the 9900k.