Years ago a built a computer from what I thought was the best parts available. I wasn’t going to use it mainly for gaming, but I wanted it to be very high performance because when I’m developing, time I have to wait is time wasted. One of those parts was the motherboard, I decided on the Asus P8Z68 Deluxe. Wow, it has four 6Gb/s SATA 3 ports.
Two of those ports are Intel, and the other two are Marvel. Whatever, I prefer Intel, I’m sure the Marvel ones are just fine.
Much later, I tried to use the two Marvel ports by hooking up with 6Gb/s SATA 3 SSDs to them, and [software] RAID-0ing them together. But something wasn’t right, I definitely wasn’t seeing the speeds I should be seeing. It wasn’t just speeds that would be good for 1 port, I was seeing less than that. How could the Marvel ports matter that much? I reconfigured my system so that I could use the Intel ports instead for the software RAID-0. Instantly incredibly better. But why?
Take a look at the data sheet for this controller. The two ports that this controller supports, is implemented via a PCIe 2.0 5Gb/s lane.
Two 6Gbps SATA 3 ports share one 5Gb/s connection.
Yup, that’s a real thing that they did, which I think is pretty misleading. Not even one port can use its full capability: for what? To say you have two additional 6Gp/s ports? Not cool Asus. I won’t even mention the part about how the controller is configured through the web browser by a process running Apache as System.