I currently have several machines running USB 3.0. Some have onboard USB 3.0 ports, and some are set up with SIG PCIe cards (Texas Instruments drivers). However, no matter what setup I use (SSD, SATA III HD in a USB 3 doc, or External USB 3 device) I can never get above 120 MB/s. The fastest seems to be a directly connected SSD drive via a USB 3.0 cable. Am I missing something? How can I see these 300 MB/s+ speeds that I have seen in tests?
What is the optimal configuration for obtaining speeds higher than 120MB/s?
What ssd's are you using? That could just be their real-world speed. There's also a way to set the power-management and stuff for the drives which can increase the speed, but I don't know which settings those are.
You could attach one of your test drives directly to your mobo. If it logs 130 MB/sec, and 120 MB/sec on USB 3.0, then all you have is a little bit of overhead. If it logs 250 MB/sec on the mobo, then you have a USB issue.
You are way ahead of the 48-50 MB/sec limit of USB 2.0, so the 3.0 is working.
I am using OCZ 4 vertex drives. I have done a few different setups including USB docks, SATA to USB3 cables and connecting them to both MOBO and cards and it seems that real world speeds of USB3 are right around 120-130MBs. If there is an optimal configuration, I have not found it.
From most of the reading I have done it seems like there is just too much driver conflict between the boards and OS. It won't be until windows and the driver manufacturers get their act together that we may see the full speed provided by the technology. Maybe Windows 8...