This figure is a calculation from the physical signaling rate ( 2.5 gigabaud ) divided by the encoding overhead ( 10 bits per byte . ) This means a sixteen lane ( ?6 ) PCIe card would then be theoretically capable of 16?50 MB / s = 4 GB / s in each direction.
32.
The data signaling rate actually observed on real networks is less than the theoretical maximum, due to the necessary header and trailer ( addressing and error-detection bits ) on every frame, the occasional " lost frame " due to noise, and time waiting after each sent frame for other devices on the network to finish transmitting.
