X399 mobo are quite costly. Also to take advantage of X399 you need quad channel DRAM kit. That adds up cost fast.
1900X was weird even during launch, as at that time 1700X/1800X were already better value.
Honestly 1900X feels to me is just AMD trying their best to salvage all usable parts. For a HEDT platform it is really bad value. Same as those quad core CPUs on the X299 platform: very stupid
If you compare them to X470 no doubt. There is no need to use Quad channel RAM for X399; Yes it does support it but it is not a requirement. I agree that the 1700/1800 were a better value but it depends on what you want. If you just want a computer I agree with phanbuey that a B450 and 2700X would be good. The 1900X was for users like me that want as many expansion slots as possible, I like to compare X399 to X570 in terms of cost/value. When I look at that I get things like this.
1. On X570 even though you get 3 NVME drives the bottom 2 are wired to the chipset.
2. On X570 if you populate 2 PCI_E 16 slots the 3rd one will run at 0
3. On X570 if you use 4 sticks of RAM they run dual channel
1. On X399 all of the expansion slos are wired to the CPU
2. On X399 you get a minimum of 3 X16 slots all wired as such (mostly 16*8*16*8 across 4 slots)
3. On X399 if you use 4 sticks of RAM they run Quad channel
Then I look at cost. The chepaest X399 board:
Buy GIGABYTE X399 AORUS PRO (AMD Ryzen Thread Ripper TR4/ATX /3X M.2/Front USB 3.1 Type C/Intel LAN/ALC1220/ Motherboard): Motherboards - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
vs X570 from the same vendor
https://www.amazon.com/GIGABYTE-ALC...?keywords=Gigabyte+X570&qid=1568639161&sr=8-4
The 1900 does look pale in comparison to it's big brothers (1920,2920,2950,2970,2990) but it is by no means a weak CPU. A first gen Ryzen chip that can OC to 4.1 across all cores at 1.325 volts is no slouch. It may indeed be salvaged parts but let's remember Dr Su said that TR4 would be the top 5% binned Ryzen chips.
First gen X399 board probably don't have enough VRM to handle Zen2 TR
$200 for 1950X would be good value. 3900X and a good B450 mobo still runs cheaper AND faster than 1920X
The 3900X is faster but in no way cheaper than the 1920. In Canada the 3900X is currently 3 times the cost of the 1920X. Using that I would pay almost $1000 for the chip and between 100 to 150 for the B450 board.
AMD Ryzen 9 3900X 12-core, 24-thread unlocked desktop processor with Wraith Prism LED Cooler : Amazon.ca: Electronics
www.amazon.ca
MSI Arsenal Gaming AMD Ryzen 1st and 2nd Gen AM4 M.2 USB 3 DDR4 DVI HDMI Crossfire ATX Motherboard (B450 Tomahawk) : Amazon.ca: Electronics
www.amazon.ca
$1121.78
vs
AMD Ryzen Threadripper 1920X (12-core/24-thread) Desktop Processor (YD192XA8AEWOF) : Amazon.ca: Electronics
www.amazon.ca
GIGABYTE X399 AORUS PRO (AMD Ryzen Thread Ripper TR4/ATX /3X M.2/Front USB 3.1 Type C/Intel LAN/ALC1220/ Motherboard) : Amazon.ca: Electronics
www.amazon.ca
$792.98