>faster than what you write in C It's hard to compare working with an HDL to working with a programming language like C; they are fundamentally different. The

>faster than what you write in C It's hard to compare working with an HDL to working with a programming language like C; they are fundamentally different. The short answer to that question is that using an FPGA can lead to massive but situational performance increases. You can't use an FPGA for everything, but when you need it, you need it. >testing then export designs into hardware This is another common use case. Some designs can be tested on an FPGA before committing that design for production as an ASIC. There's also the case where you may need to reconfigure the hardware, so you can never truly commit to an ASIC, and continue using the FPGA.