There's a fairly convincing argument to be made that AMD's Ryzen Threadripper CPUs are best suited for workstations rather than gaming rigs. AMD and Nvidia might be downplaying the relevance of multi-GPU gaming, but multi-GPU compute acceleration is bigger than ever. If you've a mind to build a Threadripper-based compute box, have a look at ASRock's X399 motherboard offerings. The company's first two Socket-TR4 motherboards are the Fatal1ty X399 Professional Gaming and the X399 Taichi. Both will accept up to four graphics cards in their metal-reinforced PCIe x16 slots.
http://techreport.com/news/32338/sti...9-motherboards
Stick four graphics cards in ASRock's X399 motherboards
4th August 2017, 06:37
Stick four graphics cards in ASRock's X399 motherboards 
