The title should not be a surprise  here in the USB Community since SuperSpeed USB is now in the market.   Still this is a news for developers working on this.


Talking  about SuperSpeed USB, the USB 3.0 standard claims that it is 10 times  faster than USB 2.0.  The  theoretical speed is 4.8Gbps (600MBps).   However looking at various  realistic speed test reports made available  by more than one developers,  it has been concluded that 3.2 Gbps  (400MBps) is the maximum achievable  speed for this standard.


The   core efficiency is dependent on a number of factors like 8b/10b   encoding, packet structure and framing, link level flow control and   protocol overhead.


Various tests performed with SLS SuperSpeed USB core indicate the speed of 400MB/s in an embedded system.


At   5Gbps signalling rate with 8b/10b encoding, the raw throughput is   500MBps.  When link flow control, packet framing, and protocol overhead   are considered, it is realistic for 400MBps or more to be delivered to   an application.


What speed can I have in my new product with SuperSpeed interface?


If  you have this question in your mind, you are at the right place.  One  of our clients evaluating the USB 3.0 core practically achieved the  speed of 2.5Gbps for IN operation and 2Gbps for OUT operation.


The raw throughput of 500MBps can be observed on the USB 3.0 Development Board (between FPGA and PHY).  The picture below shows the board:


DSC_0504-with-SMA copy copy-1.jpg


2Gbps speed is achieved on this board using SLS USB 3.0 Device core.  The block diagram of the core is given below: