"SiFive (who have ventured into making RISC-V chips)" SiFive don't make RISC-V chips, except in small volumes as a demonstration. Their business is licensing C

"SiFive (who have ventured into making RISC-V chips)" SiFive don't make RISC-V chips, except in small volumes as a demonstration. Their business is licensing CPU cores to companies that do make chips. "Horse Creek", as its naming style suggests, is an Intel product that uses licensed SiFive CPU cores. SiFive will use the chip to make high priced dev boards. We don't know yet who else will use it. The apparent success of the project is likely to get other SiFive customers to, as you say, use Intel Foundry Services instead of the traditional TSMC or Samsung. I don't know whether Intel is designing high performance RISC-V cores of their own. It's not unlikely. But there are also others announced to be providing cores to Intel Foundry Services including Rivos who are developing an M1-class RISC-V core (they have a number of Apple's core designers, including some of the founders of PA Semi who Apple bought to establish their CPU design team in the first place)